KNOWLEDGE MANAGEMENT METRICS DEVELOPMENT
by Joseph M. Firestone, Ph.D.
Knowledge Management Metrics Development: A Technical Approach
Introduction
This is one of a series of studies developing a Use Case approach to
Knowledge Management (KM). This paper is primarily focused on the problem of
developing measurement models for KM metrics in the context of a projected
information systems application fulfilling the "Perform Measurement Modeling
Task" within the "Perform Knowledge Discovery in Databases" use case.
To "drill down" to this focus I need to properly set a context involving a
number of elements. These are: the nature of measurement; its relation to KM
Metrics; the connection between KM metrics development and a business process
use case view of KM; the connection between the high level business use case:
"Discover New Knowledge in Knowledge and information Bases," and its "Perform
Measurement Modeling" Task; and finally, the connection of these to the
Distributed Knowledge Management Systems (DKMS) concept and the specific,
projected information systems application. A good bit of this paper will set
this context.
Following these preliminaries, the remainder of the paper will specify the
Perform Knowledge Discovery in Databases use case, and the Perform Measurement
Modeling Task in some detail. In the course of this specification, a number of
techniques for developing ratio-scaled measurement models applicable to KM
metrics development will be described. These will include techniques for
developing rules that map: (1) categorical variable (e.g., event or type)
values onto a ratio scaled abstract metric; (2) frequencies of an event
occurrence onto a ratio scaled abstract metric; (3) multiple indicators into a
ratio-scaled composite.
Measurement, Knowledge Management Measurement and Metrics
"Measurement is the assignment of numerals to things according to any
determinative, non-degenerate, rule." [1] Determinative means the constant
assignment of numerals given constant conditions. Non-degenerate means
allowing for the possibility of assignment of different numerals under varying
conditions.
Given this fairly broad definition it is common to distinguish
classification, linear rank ordering, and metrical measurement [2]. Metrical
measurement is quantitative. It involves assigning a real number to any
selected item in the domain of a concept. Classical examples of metrical
concepts are temperature in degrees Celsius, and length in centimeters. The
metrics in these concepts are "degrees Celsius," and "length in centimeters,"
respectively. To establish these metrics, the abstractions "temperature," and
length," are related to observational events through rules. The rules
determine the Celsius and centimeter metrical measurement scales. A
quantitative concept, the rules associated with it, and the observational
events, taken together, constitute a measurement model for a metrical scale
concept [3]. It is the measurement model, as much as the quantitative concept
and the associated observations, that establishes the metric.
In knowledge management measurement, we are trying to select and/or
formulate those concepts useful in measuring and influencing knowledge
management performance. Some concepts will prove useful because they directly
relate to core notions about the goals of knowledge management, and in that
sense, have normative significance as performance criteria. For example,
providing for the growth of knowledge is one of the goals of knowledge
management. The abstraction "growth of knowledge," is therefore a normative
concept we may seek to metricize, and establish as a performance criterion for
knowledge management.
Other concepts may at first not seem directly related to the goals of
knowledge management. But, insofar as they represent causes of the core
concepts, or possible side effects of the knowledge management process, we
will still need to measure and perhaps to metricize them, in order to explain,
predict, influence, or properly assess progress on the performance criteria.
These other concepts provide descriptive criteria for knowledge management.
The two types of criteria: normative and descriptive suggest two types of
metrics for knowledge management: normative and descriptive metrics. Though at
first blush it seems that we should be less interested in descriptive than in
normative metrics, this is not the case. Some descriptive metrics, in fact,
are likely to make the KMS "go round," and to be determinative of many of the
normative metrics. These descriptive metrics then, provide a second set of
knowledge performance metrics, a set whose members derive significance from
their role in determining the course of the KMS, not from their direct
normative significance.
KM Metrics Development and Knowledge Discovery Use Cases
Metrics development requires measurement modeling, a process of specifying
the rules relating quantitative abstract concepts to observational concepts,
thereby creating a metric. Put another way, a quantitative concept, the rules
associated with it, and the observational events, taken together, constitute a
measurement model establishing a metrical concept. It is the measurement
model, as much as the quantitative concept and the associated observations
that establishes the metric.
So, an approach to metrics development is an approach to measurement
modeling. Measurement Modeling fits within the Organizational Knowledge
Management Process (OKMP) [4] as a task within a specific OKMP business system
use case [5] called: Discover New Knowledge in Knowledge and information
Bases. This use case is part of a set of twenty-two KM use cases I have under
development and I will be call it Use Case Eleven for convenience. Here is an
outline of the use case and some of its output descriptors to provide a
context for the measurement modeling task.
Use Case Eleven: Discover New Knowledge in Knowledge and Information
Bases.
Actors: Executive, Knowledge Management Engineer, Knowledge Management
Consultant, Knowledge Engineer, IT Consultant
Structure -- The tasks comprising the use case
Retrieve strategic goals and objectives, tactical goals and objectives and
plans for knowledge discovery from outputs of earlier use cases. Sample data.
Explore Data and Clean for Analytical Modeling. Recode and transform data.
Reduce data Select variables for modeling. Transform variables for modeling.
Perform measurement modeling. Select modeling techniques for causal,
predictive, and dynamic modeling. Estimate Models using data. Validate Models.
Output
This use case further enhances the explicit organizational knowledge
base by adding new models developed in interaction with the existing knowledge
base. The enhanced knowledge base is resident in, or at least measured by,
organizational cultural artifacts -- media of various kinds. Descriptors of
the enhanced organizational knowledge base effected by this use case, as well
as descriptors relating to growth and change are:
Knowledge Base Descriptors
Knowledge Domains of knowledge components; Subsystem locus of knowledge;
Media locus of knowledge; Type of knowledge (knowledge, meta-knowledge,
planning knowledge, descriptive knowledge, knowledge about impact, predictive
knowledge, assessment knowledge); Distributed/centralized architecture of
knowledge base; Degree of integration/coherence of the knowledge base within
or between knowledge types or domains; Scope of the knowledge base within and
across knowledge types or domains; Level of measurement of attributes in
knowledge base within and across domains; Extent of quantification of
attributes in the knowledge base; Extent of logical consistency of the
knowledge base; Types of models used in the knowledge base (conceptual,
analytic, data models, object models, structural models); Types of formal
languages used in the knowledge base (set theory, mathematics, fuzzy logic,
etc.) Types of semi-formal languages used in the knowledge base (object
modeling language, knowledge modeling language, etc.); Types of methods
(features, benefits, specifications); Types of methodologies (features,
benefits, specifications); Software applications (features, benefits,
specifications, performance, interface); Type of validation of various
components of the knowledge base (logical consistency, empirical fit;
simplicity, projectibility, commensurability, continuity, coherent measurement
modeling, systematic fruitfulness, heuristic quality, comparison set
completeness, etc.); Extent of validation within each type; Composite extent
of validation of various components; Priority of knowledge components.
Performance metric on quality of organizational knowledge base
Growth and Change Descriptors
Growth/decline of various types of knowledge, Changes in knowledge
architecture centralization, Growth/decline in integration/coherence of
knowledge, Increase/decrease in scope of the knowledge base, Changes in levels
of measurement of attributes in knowledge base, Increase/decrease in
quantification of attributes, Increase/decrease in logical consistency, Change
in types of models used in knowledge base, Development in formal languages,
Development in semi-formal languages, Changes in types of methods (reduction
in costs, increase/decrease in capabilities); Change in types of methodologies
(reduction in costs, increase in scope, increase/decrease in capabilities);
Increase/decrease in IT-assisted support for decision making provided by
software applications; Increase/decrease in type of validation of various
components of the knowledge base (logical consistency, empirical fit;
simplicity, projectibility, commensurability, continuity, coherent measurement
modeling, systematic fruitfulness, heuristic quality, completeness of the
comparison set, etc.); Increase/decrease in extent of validation within each
type; Increase/decrease in composite extent of validation of various
components. Performance metric on discovery of new knowledge.
In the first instance, an approach to metrics is to specify further what is
entailed in the measurement modeling task. And since the measurement modeling
task is integrated within the broader context of Use Case Eleven, we also need
to further clarify this context on which measurement modeling is dependent. At
this point we could proceed in either of two directions.
We could specify OKMP Business Process Use Case Eleven in more detail and
analyze measurement modeling as a task within this use case. Or we could move
to a more concrete level of analysis and consider measurement modeling as a
task in knowledge management software applications.
We choose to continue this conceptual development at the more concrete level
of the software application for three reasons. (a) We need to go there anyway,
eventually. (b) Measurement modeling is closely related to analytical modeling
and data mining, two subjects closely identified with automated analysis and
software applications. And (c) moving to the software application level will
allow specification of more of the information systems application underlying
metrics development than if we continued the analysis at the OKMP level.
In developing the idea of measurement modeling or metrics development as
part of a software application, we need the concept of an Information Systems
Use Case. This concept is defined by Jacobson [6] as "A behaviourally-related
sequence of transactions performed by an actor in a dialogue with the system
to provide some measurable value to the actor." A behaviorally related set of
information system use cases, in turn, constitutes an information systems
application supporting a business process through its use cases.
Measurement modeling is not only a task in the Knowledge Discovery use case
of the OKMP; it is also a task in the use case of the information systems
application supporting the OKMP. This generic information systems application
is called the Distributed Knowledge Management System (DKMS). [7] Its Use Case
Eleven is called "Perform Knowledge Discovery in Databases (KDD)." [8]
Distributed Knowledge Management Systems (DKMS) and Automated Knowledge
Bases
An OKMP may be supported by a software application system that manages the
integration of distributed objects into a functioning whole producing,
maintaining, and enhancing an automated knowledge base. This software
application is the DKMS. The functionality of a DKMS is specified by a set of
DKMS use cases partially automating the knowledge management use cases of the
OKMP. These DKMS use cases then, are conceptually distinct from OKMP use
cases.
An automated knowledge base is the set of data, validated models,
metamodels, and software used for manipulating these, pertaining to an
organization, produced either by using a DKMS, or imported from other sources
upon creation of a DKMS. A DKMS, in this view, requires a knowledge base to
begin operation. But it enhances its own knowledge base with the passage of
time because it is a self-correcting system, subject to testing against
experience.
The DKMS knowledge base is a subsystem of the broader organizational
knowledge base. But it is a subsystem that will grow in size and importance in
pursuing the goals of improved knowledge management and growth in
organizational knowledge. The DKMS must not only manage data, but all of the
objects, object models, process models, use case models, object interaction
models, and dynamic models, used to process data and to interpret it to
produce an organization's automated knowledge base. It is because of its role
in managing and processing data, objects, and models to produce a knowledge
base that the term Distributed Knowledge Management System is so appropriate
for this software application.
The Perform KDD Use Case
Here is a detailed exposition of the Perform KDD use case. Its importance
for metrics development is to make clear the context of measurement modeling
and its dependencies on the tasks that come both before and after measurement
modeling in the use case sequence.
Actors: Executive, Knowledge Management Engineer, Knowledge Management
Consultant, Knowledge Engineer, IT Consultant The Knowledge Management
Engineer, and Knowledge Management Consultant will perform "what-if"
simulations of policy impact, develop forecasts, and perform model adjustment,
adaptation, and refinement of previously formulated models. These tasks may
require that these actors execute a highly automated form of KDD/data mining
workflow, where the actor is led through the data mining process according to
a fixed set of procedures and dialogs in order to adjust, adapt, or refine
previously formulated models.
The Knowledge Engineer performs the same tasks as the Knowledge Management
Engineer, or Knowledge Management Consultant, except this role adds a more
flexible KDD/data mining work flow beginning with data input, moving through
various data processing and KDD stages including model estimation and model
validation. The Knowledge Engineer will have complete flexibility in
performing the data mining workflow and exercising professional judgment in
arriving at estimated and validated models.
Structure
Retrieve and display strategic goals and objectives, tactical goals and
objectives, and plans for knowledge discovery from outputs of Use Cases
One-Four.
The actor interfaces with dialogues displaying the plans and priorities for
new knowledge discovery. Based on this examination the actor selects the
business domain area of the discovery effort.
Select entity objects representing business domains to be mined for new
knowledge. Once the area of investigation is selected, the actor searches for
domain entity objects that may be relevant to the investigation, and selects
from among them the targets of the KDD process.
Sample data
The actor will work through a dialogue to select samples of the
data to be mined within the entity objects selected. A full range of one-of-n
and random sampling options should be available through the GUI interface.
Explore data and clean for modeling
This task refers to basic exploratory data
analysis. This is a task that requires considerable expertise and judgment to
perform well, and it also requires access to a diversity of analytical
techniques that would be used in a relatively free-wheeling manner. Therefore,
the Knowledge Management Engineer, and Knowledge Management Consultant will
not perform this data mining task. It is restricted instead to the Knowledge
Engineer Role.
The Knowledge Engineer needs access to, and appropriate dialogues for:
general purpose descriptive statistics, specialized descriptive statistics and
diagnostics, graphs for exploratory data analysis, tests for fitting
probability distributions to data, descriptive statistics and graphics coupled
with segmentations by grouping variables, categorization of continuous
variables, spreadsheet-like browsing of data, point-and-click facilities to
switch from data to graphics, comprehensive sets of options in computing
correlations between and among variables, including the ability to handle
missing data, graphics for visualizing correlations and correlation matrices,
descriptive statistics and graphics for blocks of data selected while browsing
the database, an interactive probability calculator to allow an actor to
explore distributions of segments of data, t- and other tests of group
differences in means, frequency tables, cross-tabulation tables,
stub-and-banner tables, multiway tables, graphics, and statistical tests
correlated to the tables, a comprehensive set of non-parametric statistical
tests and associated graphics, and distribution fitting with statistical tests
and associated graphics. Once subtasks related to dialogues representing these
techniques are performed, responses from the software must include
attractively formatted and highly customizable reports for the Knowledge
Engineer. The reports must be integratable with other documents, and also
highly editable for presentations and publications.
Cleaning data for modeling, is very different from cleaning data in the
course of creating a data warehouse. Assuming that data warehouse-related
cleaning has been done, specialized data cleaning for data mining is cleaning
for the purpose of adapting to the data mining software or the analytical
purpose of the data mining task. Thus, the actor may need to remove missing
data codes that are inconsistent with the data mining software, even though
they fit the data warehousing software. It may also be necessary to scrub the
data of certain specialized fields that are inconsistent with data mining.
Finally it may be necessary to remove duplicate records that have value for
data warehouse reporting, but are in conflict with the specific purposes of an
analysis, and would distort the results of model estimation. The software must
provide support for the actor to perform this type of specialized cleansing
for data mining.
Recode and transform data
The Knowledge Engineer follows exploratory data analysis and data cleansing
with recoding and transformation of data variables. The model manager will
often recode continuous variables to ordinal or categorical ones, or re-code
categorical variables to consolidate categories. The model manager will create
"dummy" variables out of both categorical and continuous variables. The
capacity for recoding must be one that fully supports all common logical
operations and conditional statements of unlimited complexity.
Data transformations will be performed to create distributions that better
fit statistical norms, to modify outliers, and to handle missing data. The
data transformation capability required here must support all standard
mathematical functions, a large variety of statistical functions, conditional
operations, variable names, comments, and missing data. The Knowledge
Engineers will both transform existing variables and define new ones using the
facility. The Knowledge Engineers will also write their own data
transformation algorithms, and/or interface the software with external
software containing other data transformation algorithms. The data mining
software must support these activities.
Both the recoding, and data transformation activities will be highly
interactive. Results of recoding or data transformation activities must be
immediately observable in tabular or graphic form, since Knowledge Engineers
will move from action to inspection of results and back, in a continuous and
rapid workflow.
Reduce data
While performing recoding and data transformation, the Knowledge Engineer
also makes decisions about which variables are relevant to the specific data
mining problem providing the context of the use case. The Knowledge Engineer
might base the relevance decisions on the results of previous activities
supplemented by intuition, or alternatively, a formal evaluation procedure
rating variables for relevance to the data mining problem might be employed.
If the latter scenario is selected by the actor, the Analytic Hierarchy
Process (AHP) [9] would be used to derive the relevance ratings, since this is
a prioritization problem. The software capability to handle this process would
have been implemented for earlier use cases of the DKMS. For this use case,
exactly the same software might be used, or if this alternative is not
specifically focused enough on the problem of relevance ratings for variables,
a template would be derived specifically for this use case.
Once either intuition, or AHP-based decisions are made to reduce the data
variables involved in the data mining process, the remaining data variables
are subject to empirically-based methods of data reduction. Knowledge
Engineers use a variety of techniques in performing this next task including:
further descriptive statistical analysis, further exploratory data analysis,
contingency table analysis, correlation analysis, cluster analysis, principal
components analysis with rotation, and multiple and stepwise linear
regression.
The objective in performing these tasks are to know intimately the shape
of the distribution of each independent and dependent variable, and to learn
about their degree of redundancy. The Knowledge Engineer also tries to select
variables that measure different things in different ways, or at least the
same thing in different ways, and also determine whether the variables
selected will meet the distributional assumptions of the modeling techniques
being considered.
Select variables for modeling
This step is one of further work in variable selection. Here attention
focuses on techniques such as multiple and stepwise regression in preliminary
attempts to estimate a final model, while also determining whether additional
variables can be pruned from the model.
Transform variables
By the end of task (f) the Knowledge Engineer has reduced the data set by a
great deal, often by as much as ninety percent (90%). A much more exacting
effort is then made to model the non-linear relationships among variables.
Transformations will be performed to derive nonlinear forms or combinations of
the independent variables, to be used in the remaining stages of modeling.
These non-linear transformations are often dictated by theory, but sometimes
transformations are employed based on hunches or desires to experiment with
new functional forms.
Perform measurement modeling
The Knowledge Engineer now moves to a stage of explicit measurement
modeling, where attempts are made to model the relations between and among
data variables and abstract attributes they are supposed to measure. The more
specific objective is to formulate models that define tight clusterings of
data variables around derived abstractions. For measurement relations that are
linear in their functional forms, the well-known techniques of structural
equation and path modeling are often used. If nonlinear measurement modeling
is involved, a diversity of techniques including fuzzy measurement modeling,
bayesian belief networks and neural networks are appropriate.
If specific measurement models prove unsatisfactory, the Knowledge Engineer
may iterate within the data mining use case, by returning to earlier tasks and
re-transforming variables. Another favorite alternative, is to subset the data
into more homogeneous groups of cases that may produce more satisfactory
measurement models. Group Clustering techniques are used for this purpose.
Clustering techniques must be selected by the Knowledge Engineer, and then
applied to derive more homogeneous clusters. Measurement modeling may then be
attempted once again, within each homogeneous group of cases.
Select modeling techniques
When measurement models are formulated, techniques must be selected for
causal or predictive modeling. The Knowledge Engineer must select from a range
of techniques now provided by statistical packages including: various forms of
multiple regression, analysis of variance, classification and regression
trees, log-linear analysis, general non-linear estimation (including probit
and logit analysis), canonical correlation and regression analysis,
discriminant and canonical discriminant analysis, survival/failure-time
analysis, time series analysis, and forecasting methods, structural equation
modeling and path analysis. In addition, the Knowledge Engineer needs to be
able to select from a number of techniques based on more recent fields of
analytical research such as: neural networks, fuzzy engineering, genetic
algorithms, chaos and fractal theory, graphical belief models, and case-based
reasoning.
Estimate models
Once the modeling technique is selected, the Knowledge Engineer uses the GUI
interface to point the technique(s) to the data set to be mined, runs the data
mining software applying the model estimation technique, and receives the
results in tabular, graphic and other visual formats.
Validate models
Results of model estimation are likely to conflict both within and across
modeling techniques. Since a good analysis will provide many different points
of view on the data, such conflicts are to be expected and welcomed as part of
the ordinary procedure of model estimation. The validation task is one of
conflict resolution, where the Knowledge Engineer decides on acceptance of one
or more models for future application. This means the Knowledge Engineer must
walk through a multi-criterion decision process to rate or at least rank
candidate models, and to specify a cut-off point for excluding models from
future application.
In this decision process the Knowledge Engineer will first develop, revise
or reengineer an attribute hierarchy specifying the validity concept [10]. The
attribute hierarchy will have validity at its first level and then will
specify a second level concept cluster containing the components of validity
from the perspective of the Knowledge Engineer. In turn, each component of
this second level cluster will be specified by a third cluster, and so on
until each component of the validity concept is specified to the point where
quantitative data or logically consistent judgment-based ratings may be
specified.
In specifying the attribute hierarchy, the actor will again apply the AHP.
But it is here applied to validity assessment, rather than to developing a
hierarchy of goals and objectives. Once the hierarchy, including its priority
weights, derived from pair comparison ratings is developed, it will be applied
to assess validity. Actors will perform such assessments by applying global
weights to values of the bottom level components of the hierarchy. These
values will be test statistics of goodness of fit of models, or tests of
statistical significance, or other data on test criteria provided by the
various statistical and analytical algorithms used with the workbench.
In relation to components where such "operational" measures of validity do
not exist, actors will use the AHP pair comparison rating and ratio scaling
facilities to produce such measurement. When all measurements are specified,
existing quantitative measurements will be normalized to the same scale as
ratio scale ratings. Finally, measurements of validity for each competing
model in a model comparison set will be derived by using criterion values and
global weights to aggregate a global measurement of validity for each model.
All criterion values, weights, hierarchy relationships and hierarchy metadata
will be saved to a commercial database.
Actors will review and report on validity assessments by using a set of
standard reports displaying various aspects of validity hierarchies. Actors
will also use ad hoc reporting to construct new views of the validity data and
metadata. Graphics, and charts as well as tables will be provided for this
reporting subtask. Following examination of results of the validity
assessment, actors will decide on cutoff levels for valid models to be
retained for future applications and for use by Knowledge Management
Engineers, and Knowledge Management Consultants. A GUI dialog will assist
actors in making this choice by summarizing the results of the validity
assessment and by providing access to the full set of reporting capabilities
on validity data and metadata. The dialogue will also allow the actor to save
the cutoff decision to the database and to apply any cutoff criterion
formulated by the actor to future validity decision-making.
To facilitate the actor's attempts to construct validity hierarchies, the
software will offer a baseline validity hierarchy developed for the
application. This template will specify all of the clusters and their
components, but will provide equal weighting for each component in the
hierarchy as a set of default values. It will then be up to the individual
Knowledge Engineers to customize their own hierarchy by deleting or adding
components and providing weights. The various subtasks of the validate models
task are listed below.
Enter, edit, or review the highest level attributes for specifying validity
in an analytic hierarchy interface. Rate the highest-level validity attributes
relative to each other with respect to validity. Enter, edit, or review the
highest level attributes for further specifying each highest-level validity
attribute. Rate the attributes specified in (3) above, relative to each other
with respect to each highest-level validity attribute to which they
contribute. Enter, edit, or review the next lower-level objectives
contributing to each attribute specified in (3). Rate these next lower-level
attributes (those specified in (5)) relative to each other with respect to
each attribute specified in (4) above. Repeat (5) and (6) until the lowest
level attributes for specifying validity are selected and rated. Compute and
save the analytic hierarchy of attributes. Report on results of (1) to (8)
above, the various levels of validity-related attributes, their relative
importance, and relations to each other. Retrieve and display lowest level
validity attribute values, where these are provided by algorithmic software.
Provide missing lowest-level attribute level validity values by performing
ratings directly pair-comparing models in the comparison set, against one
another with respect to the lowest level validity criterion whose measurement
values are being estimated. Use the AHP rating methods to derive these
validity values, and to provide consistency measures of the ratings. Derive
global values for the lowest-level validity attributes by applying the global
importance weights to the results of the ratings in (11), and to the results
provided by algorithmic software. Compare models according to their global
validity scores. Determine cutoff points or range for designating models as
valid. Designate models as valid. Save results to the metadata repository.
Repeat a specific data mining process on the same or new data
This task is the basis for the Knowledge Management Engineer's, and
Knowledge Management Consultant's involvement in the data mining process. They
need to be able to adjust, refine, and adapt models previously formulated by
the Knowledge Engineer. In this task, they will browse models in a model
repository, or metadata about these models. Based on such metadata, the
Knowledge Management Engineer, and Knowledge Management Consultant will select
both models and associated data sets to work with. They will execute
selections through the measurement modeling task in an automated fashion. That
is, when the Knowledge Management Engineer, or Knowledge Management Consultant
executes a model, all of the earlier decisions made by the Knowledge Engineer
who initially formulated a particular model will be repeated on both old and
new data records. The Knowledge Management Engineer, and Knowledge Management
Consultant will not be allowed to add any new data variables to the analysis.
When the model selection task is reached, the Knowledge Management Engineer,
and Knowledge Management Consultant will use a wizard to decide whether a
modeling technique not previously used will be included in the new analysis.
If a new technique is selected through use of the wizard, it will be used
along with the old techniques to re-estimate models.
In the validation task finally, the Knowledge Management Engineer, and
Knowledge Management Consultant will be guided in final model selection by a
wizard incorporating the previous weightings and criteria used by the
Knowledge Engineer. They can use the wizard to include models for future
application, if these were selected during the validation task by using the
evaluation criteria incorporated into the wizard by the Knowledge Engineer.
But they will not be able to change the evaluation criteria, or priority
weights specified by the Knowledge Engineer, or either add or delete models
without using the Wizard.
The "Perform Measurement Modeling" Task
The Knowledge Engineer now moves to a stage of explicit measurement
modeling, where attempts are made to model the relations between and among
data variables and abstract attributes they are supposed to measure. The more
specific objective is to formulate models that define tight clusterings of
data variables around derived abstractions, and that metricize these
abstractions to establish ratio scales [11].
Open the concept mapping, cognitive mapping, knowledge mapping, graphical
belief modeling or semantic networking dialog, and create, label, and define a
new node [12].
Not that the above techniques are the same, but their function in
graphically representing a network of concepts related by propositions is
similar. Use of one of the techniques to specify concepts is both more
effective and more economical for concept specification. The measurement scale
level intended for the new node is specified as part of this step.
Develop a network of abstract concepts encompassing the quantitative concept
to be modeled, by establishing new nodes for related concepts and linking them
to the original concept.
A technique should be used that supports fuzzy cognitive mapping [13], as
well as crisp cognitive mapping, and that allows distinctions among different
forms of entailment such as logical entailment or causal entailment.
Select data variables as candidate measures of the original concept
The task should support database browsing for information about candidate
variables, and an interface that allows drag-and-drop selection of the
candidates. Results of the previous concept specification tasks should support
selection of tables or classes relevant to the underlying concepts. The
existing object or data models, if properly done, will tend to associate
candidate data variables in the same classes or tables.
Open dialog guiding actor in specifying rules relating abstract and data
variables in such a way that values of the data variables can be used along
with the rules to compute quantitative scores for the concepts.
This is an involved dialog providing for a number of options. Frequently,
rule specification for metrics is very direct, even simple. For example,
"extent of accessibility of the hierarchy" produced by use case one to
knowledge management consumers can be measured by the percentage of
organization actors who have documents detailing the hierarchy, or who can
access it through their workstations either locally, or over a network. The
rule of correspondence in this case associates extent of accessibility with
percentage of individuals having access. Each additional individual increases
the percentage and the extent of accessibility by corresponding amounts.
More generally, though, metrics development may require: (1) a rule that
will map categorical variable (e.g., event or type) values onto a ratio scaled
abstract metric; (2) a rule that maps frequencies of an event occurrence onto
a ratio scaled abstract metric; or perhaps (3) a combination of multiple
indicators into a composite, mapping data variable values to values of an
abstract metric. Here are procedures for developing ratio scaled metrics for
these three situations specified in terms appropriate for the DKMS application
context.
(1) The actor opens a dialog for establishing a ratio scale metric for an
abstract concept from specified individual categorical data attribute values.
The actor activates the rating task and selects the categorical attribute
values as the object of judgmental ratings. Upon selection, these are
presented to the actor in a series of pair-wise comparisons with other data
attribute values on a priority scale relative to the abstraction.
The comparative judgments will split 100 points between each pair member
(the constant sum comparison method), to rate the relative priority of one
pair member against another.
Alternatively, the actor will assign a value to the right-hand member of a
pair by making a proportional comparison to a fixed value of 100 given to the
left-hand pair member. Alternatively, the actor will rate relative priority by
adjusting the height of bars on a GUI control representing the relative
importance of each pair member. Whichever, method is selected by the actor.
The results of ratings will be displayed by the software using all three
methods for the actor's review of ratings.
The actor enters the pair-wise comparisons using one of the rating methods,
until all ratings are completed. The actor then saves the judgments, and after
doing so, causes the software to assemble these into a positive reciprocal
matrix. From this matrix it computes ratio-scaled priority ratings for each of
the categorical attribute values, along with a measure of the consistency of
the matrix of judgments on which the scale is based [14].
The result of the above procedure is a set of rules of correspondence of the
form "if E then S" where: E is the event, event sequence, or event
co-occurrence represented by the value of the categorical observational
variable; and S is the value of the abstract quantity on a ratio scale [15].
In fact, the set of these rules of correspondence establishes the metrical
standard of the underlying concept the actor is constructing.
(2) What if a categorical variable can be aggregated to produce event, event
co-occurrence, or event sequence frequencies? Then the actor proceeds to open
a dialog supporting formulating a "principle of correlation," [16] between a
data variable and an abstraction. If E Then S, is a rule of correspondence;
then S= a + bf(E) (where S is the abstract scaled variable, f is some
unspecified function, linear or non-linear as appropriate, and E is an event
frequency variable), is the principle of correlation relating event
frequencies to values on the abstract scale.
This general form encompasses all individual rules of correspondence of the
if-then form relating any possible event frequency to an S-value. An actor has
unlimited freedom in specifying a principle of correlation, which is just
another hypothesis among many in a measurement model. The application should
therefore support selection of any of a diverse set of commonly available
functional forms, plus the ability for actors to specify a function of their
choosing as a principle of correlation.
To help arrive at a principle of correlation, the actor should again apply
pair comparisons, but now to event frequencies rather than single events. This
will produce individual rules associating ratio scaled values with particular
event frequencies, but no principle of correlation.
To get to a principle of correlation, the actor uses the application to
graph event frequencies against scale values, and to non-linearly regress
scale values against frequencies. The regression result is the principle of
correlation. Once the principle of correlation is specified for each type of
event establishing the original ratio relationships, the measurement model
relating events and event frequencies to the underlying linear order is
complete, though the model is purely hypothetical and requires external
validation.
(3) For the composite case, here are two alternative techniques.
(i) Assuming the proposed component attributes of a composite are not
statistically correlated, one procedure begins with the actor performing pair
comparisons of the relative ability of each of the attributes of the composite
to represent the abstract quantity. The procedure is no different from the one
for categorical attributes up to this point. Once logically consistent
judgments are forthcoming, it produces a set of relative ability ratio scaled
values of weights to be applied to the attributes in computing the composite.
The actor next computes a ratio scale from an algorithm for computing the
composite. The algorithm normalizes and translates each of the attributes so
that their values prior to the computation of the final scores are calibrated
to one of the attributes already defined as a ratio scaled metric.
The calibration is done through simple linear regression against the
criterion attribute variable, and is part of the algorithm. The algorithm then
proceeds to compute the composite by weighting the transformed data variables,
or transformed functions of these variables (if theoretical considerations
dictate using something other than a simple linear composite), and then
summing the weighted transformed scores. The result is a ratio scale since
both the relative ability weights and all the component attributes in the
composite have been defined on such a scale.
An alternative to using regression against one of the component attributes
in order to normalize all attributes to the same input ratio scale, is to use
a ratio-scaled criterion variable for regression that is external to the
composite. The zero point for such a criterion may be established
non-arbitrarily, if there are enough objects available having the ratio scaled
abstract attribute to support another round of pair comparisons.
Specifically the actor can rate objects comparatively in relation to the
attribute being measured. Following consistency tests and computation of ratio
scale values, an attribute directly scaling the objects relative to the
underlying attribute is produced. At this point the actor completes the
procedure by regressing the composite predictor of the abstract attribute
against the directly scaled attribute, or by regressing the attributes
entering the composite directly against the criterion attribute. Once the
composite is calibrated in this way, it can be used without the criterion
variable to produce ratio scaled values.
(ii) The second alternative technique for producing ratio scaled composites is
based on fuzzy measurement modeling.
Assuming that quantitative component attributes have already been selected
for the proposed composite (for example, a multi-attribute performance
measure), the actor's first step is to map these quantitative attributes into
fuzzy linguistic variables, composed of fuzzy term subsets. This mapping is
called fuzzification.
A fuzzy linguistic variable is an abstraction that maps a quantitative
variable into a set of overlapping, categorical, subdivisions. The overlapping
categories are the values of the linguistic variable. A fuzzy term subset is
one of these linguistic categories. Each fuzzy term subset is specified by a
surface, called a membership function, which maps the values of the underlying
quantitative variable into the interval [0,1].
The significance of the mapping is that it measures the extent to which a
value of the underlying quantity is a member of the fuzzy term subset whose
surface determines the mapping.
For example, the value 0.4 units for degree of existence of tactical
objectives maps to both the low and medium term sets. Its degree of membership
in the low term set is 0.4. Its degree of membership in the medium term set is
0.6. Every other value on the horizontal axis is also mapped by one of the
overlapping membership functions.
Once the mapping of quantitative to fuzzy linguistic variables and term sets
is complete for all components of the composite, the actor is guided by the
system in formulating the output variable. This variable may be a performance
index, such as the metric on the quality of the knowledge base mentioned in
Use Case Eleven. The actor selects the fuzzy term sets for the performance
index, the shape of the membership functions, and the appropriate metric scale
of the output quantitative variable. Degree of performance of any use case has
a theoretical zero point, and full performance has a theoretical value of one,
so the actor can specify the interval between zero and one as the range of
values for the metric.
Next, the actor uses the system to formulate fuzzy rules connecting the
input linguistic variables to the output. In the composite situation each of
these rules have the form: If LVI(1) is A(1), and LVI(2) is A(2), and . . .
LVI (n) is A(n) then LVO is B(1), where the LVI(1) . . . LVI(n) are linguistic
variables input, A(1) . . . are fuzzy subsets (term sets), LVO is the
linguistic performance output variable, and B(1) is a fuzzy output subset. The
rules are linguistic expressions. An abbreviated example of such a rule is:
If degree of existence of the hierarchical network is high, and depth of the
hierarchy is moderate, and dissemination of the hierarchy is medium, than
performance in constructing and disseminating the hierarchy is moderate.
In a composite with ten attributes, with seven term subsets per variable,
and one output variable also with seven term sets, the number of possible
rules is more than 282 million, a prohibitive number to model. Fortunately,
Kosko [17] has shown that all multi-antecedent rules in a Fuzzy Associative
Memory (FAM), can be composed from single antecedent rules, and therefore add
no new information. In the ten attribute example, there are 490 such rules, a
much more manageable number. The system will automatically generate the rules
in a manner transparent to the actor.
Once the rules are generated, the actor needs to specify the degree of
support for each rule. Degree of support is used in fuzzy inference to specify
the actor's hypothesis about the validity of each rule. Degree of support can
therefore be used to weight each rule in the process of inference from input
to output fuzzy term subsets.
To get degree of support, the actor performs pair comparisons of the
relative ability of each of the attributes of the composite to represent the
abstract quantity as in section (i), above. The procedure produces a set of
relative ability ratio scaled values of weights. These are the degrees of
support to be applied in fuzzy inference. Degree of support is constant for
all rules of a given linguistic variable, but varies across linguistic
variables. In the case of the ten attribute composite, there would only be ten
weights, each applying to 49 rules. The system would assign weights to rules
for the actor.
When fuzzy inference is used in this type of measurement model, the scale
values of the original attributes entering the composite are transformed into
ratio scaled membership function values (varying between zero and one) by the
membership functions specifying the term sets. A non-zero membership function
value of a member of a term set activates a fuzzy rule connecting a linguistic
antecedent with a consequent to the degree represented by the membership
function value. This degree of membership value is passed from the antecedent
to the consequent in the inference process. So when inference is carried out,
both a term set value (e.g., "performance is moderate") and a degree of
membership value (e.g., 0.8) in the consequent term set, are deduced when
using a fuzzy rule.
The values generated from a single rule are one element in a fuzzy surface
generated by the full set of rules as they are applied to data describing an
object. This fuzzy surface is the full information outcome of the fuzzy
inference process.
To get from this outcome to a single ratio scale composite value, the actor
needs to perform de-fuzzification. In de-fuzzification, the output surface
generated by the fuzzy inference process is transformed into a single value
most representative of the surface. Depending on the specific situation,
different concepts of "most representative" can lead to different
de-fuzzification calculations.
Here the centroid method of arriving at a single-valued output of the
measurement process will be used. This method is essentially an average of the
degree of membership values passed from the antecedent to the consequent terms
during the fuzzy inference process [18]. Since the method operates on ratio
scale values produced by the inference process, and computes a result based on
the membership function values, the result is itself a ratio-scaled metric. In
fact, in the performance index case mentioned above, the performance outcome
values inferred by the fuzzy measurement model will vary over the interval
from zero to one.
Perform internal validation of knowledge management metric.
The consistency measure is reported to the actor, along with the option to
revise ratings by recycling through the ratings process, and advice on the
need to revise ratings if the consistency measure exceeds a threshold level.
When the actor is satisfied with the consistency of a set of ratings, the
actor indicates acceptance.
Consistency across judges is also an aspect of internal validation. A dialog
should support processing of comparisons of judgment matrices across judges,
and provide measures of agreement/disagreement.
Perform external validation.
Strictly speaking, external validation is not a part of this task. It is
part of the general KDD use case. There is no successful measurement modeling
without KDD. Metrics are part of the model network that gets tested in an
attempt to establish new knowledge. Metrics are finally established as valid
only when the causal and dynamic models they are associated with survive
testing.
Conclusion
This White Paper:
Characterized the nature of measurement and metrics development for
knowledge management; showed how the OKMP and its use cases are related to the
software application level of Distributed Knowledge Management Systems;
presented the Perform Knowledge Discovery in Databases (KDD) use case which
would provide the context for KM Metrics development at the software
application level; and presented a general characterization of the Perform
Measurement Modeling task within the Perform KDD use case focusing on
development of ratio scaled metrics of quantitative abstractions. Here are
some possibilities for future developments.
First, KM Metric Templates based on the measurement modeling approach and
methods would be a very desirable direction for new work. It is obvious that
specific KM metrics will be tied to specific organizational contexts. Domain
details affecting KM metrics will differ across organizations. Also, in the
area of performance metrics, value interpretations entering composite
performance metrics will differ across individual organizations. In spite of
the diversity of specific KM metrics across organizations, it should, shortly,
be possible to define general types of metrics: for example, use case
performance metrics that are structurally similar across organizations. If
these are formally defined as software patterns and are instantiated as
user-oriented template components, they would then be ready for customization
in organizational contexts.
Second, this paper has not covered very much in the area of KM Metrics
conceptualization. It hasn't covered either KM domain metrics or business
domain-based knowledge management metrics. Such metrics are necessary to
provide utility to the abstractions I've provided here. The first step in
developing these is conceptual specification of metrics (as distinct from
data) in various business domains including KM. A future White Paper in this
series will provide conceptualization in KM itself. In addition, the Knowledge
Management Consortium (KMC) KM Metrics Task Force [19] is currently working
vigorously in this area. But lots more effort is needed both in KM and in
other domains.
Third, in this development, I haven't given attention to the environment of
the OKMP, or to any other organizational processes and their relation to the
OKMP. Clearly, a "balanced scorecard" viewpoint for organizations is needed to
place KM Metrics in the broader context. Kaplan and Norton [20] distinguish
Financial, Internal, Customer, and Learning and Growth perspectives on
organizational processes essential to an overall strategy. Knowledge
Management clearly fits within, if it does not define, the Learning and Growth
aspect of their framework. If this is true, Knowledge Management outputs, the
products of the use cases of the OKMP, will impact on other processes. I have
not treated these impacts in this study of KM Metrics; but, because of its
significance in measuring knowledge management benefits or costs to other
processes in organizations, this is an important area for extending the
present work.
Finally, if KM takes hold as a field, one of its main thrusts will be KM
metrics development and implementation. In developing the above conception of
the measurement modeling task, I've done some of the specification necessary
for a software application in the area of KM Metrics development. It is
doubtful that such an application should stand alone, but it is applicable as
a part of an application fulfilling the "Perform KDD" use case. As yet no data
mining products offer an application to facilitate measurement modeling and KM
Metrics development.
White Paper No. Ten
References
[1] Brian Ellis, Basic Concepts of Measurement (Cambridge, England: Cambridge
University Press, 1966), P. 41
[2] Carl G. Hempel, Fundamentals of Concept Formation in Empirical Science
(Chicago: University of Chicago Press, 1952), 54-55.
[3] Joseph M. Firestone and Richard W. Chadwick, "A New Procedure for
Constructing Measurement Models of Ratio Scale Concepts," International
journal of General Systems, 2 (1975), 35-53.
[4] The OKMP, along with a number of other key concepts of knowledge
management, is defined in my "Basic Concepts of Knowledge Management," White
Paper at www.dkms.com/KMBASIC.html.
[5] A Business System Use Case is defined by Jacobson as "A sequence of
transactions in a system whose task is to yield a result of measurable value
to an individual actor of the business system." See Ivar Jacobson, Maria
Ericsson and Agneta Jacobson., The Object Advantage: Business Process
Reengineering with Object Technology (Reading, MA: Addison-Wesley, 1995), P.
343
[6] Ibid.
[7] I introduced the DKMS concept in two White Papers "Object-Oriented Data
Warehouse," and "Distributed Knowledge Management Systems: The Next Wave in
DSS." Both are available at
www.dkms.com/White_Papers.htm.
[8] See Usama M. Fayyad, Gregory Piatetsky-Shapiro, Padhraic Smyth, and
Ramasmy Uthurusamy (eds.), Advances in Knowledge Discovery and Data Mining
(Cambridge, MA: M.I.T. Press, 1996).
[9] The hierarchy is an analytical hierarchy as defined by Thomas L. Saaty,
The Analytic Hierarchy Process: Planning, Priority Setting, resource
Allocation, 2nd Edition (Pittsburgh, PA: RWS Publications, 1990).
[10] The proposal is that the AHP be used to define the meta-knowledge
validity concept, in much the same way as it is used to define other value
interpretative concepts in terms of an analytic hierarchy.
[11] See S. S. Stevens "On the Theory of Scales and Measurement," Science,
103, (1946), 667-680.
[12] R. White and R. Gunstone, Probing Understanding (New York: Falmer Press,
1992), Bart Kosko. Neural Networks and Fuzzy Systems (Englewood Cliffs, NJ:
Prentice-Hall, 1992), Robert Axelrod, (Ed.) The Structure of Decision
(Princeton, NJ: Princeton University Press, 1976), Ted Kesik, Knowledge
Mapping"
www.acs.ryerson.ca/~bsc/kmapmain.htm, Russell G. Almond,
Graphical Belief Modeling (London, UK: Chapman & Hall, 1995), Francis
Heylighen, "Structuring Knowledge in a Network of Concepts,
pespmc1.vub.ac.be/Papers/StructuringKnowledge.htm.
[13] Stephen T. Mohr, "Software Design For a Fuzzy Cognitive Map Modeling
Tool," Rensselaer Polytechnic Institute, Fall 1997, Master's project.
[14] Saaty, 1990, Warren S. Torgerson. Theory and Methods of Scaling (New
York: John Wiley, 1958), Firestone and Chadwick, 1975.
[15] Firestone and Chadwick. Ibid. Pp. 45-47.
[16] Ellis, 1966, P. 96.
[17] Kosko, 1992, Pp. 322-326.
[18] Ibid. Pp. 315-316.
[19] Work with the KMC KM Metrics Task Force led to this paper. See KMC's Web
site at www.km.org.
[20] Robert S. Kaplan and David P. Norton. The Balanced Scorecard (Boston, MA:
Harvard Business School Press, 1996).
Biography
Joseph M. Firestone, Ph.D.
CEO, Chief Scientist
Executive Information Systems Inc (EIS)
703-461-8823, eisai@home.com
Joseph M. Firestone, Ph.D. is CEO and Chief Scientist of Executive Information Systems (EIS)
Inc. Joe has varied experience in consulting, management, information
technology, decision support, and social systems analysis. Currently, he
focuses on product, methodology, architecture, and solutions development in
Enterprise Information and knowledge Portals, where he performs Knowledge and
knowledge management audits, training, and facilitative systems planning,
requirements capture, analysis, and design. Joe was the first to define and
specify the Enterprise Knowledge Portal Concept. He is widely published in the
areas of Decision Support (especially Enterprise Information and Knowledge
Portals, Data Warehouses/Data Marts, and Data Mining), and Knowledge
Management, and has recently completed a full-length industry report entitled
"Approaching Enterprise
Information Portals." Joe is a founding member of the Knowledge Management
Consortium International (KMCI), Editor of the new KMCI Journal, Chairperson
of the KMCI’s Artificial Knowledge Management Systems SIG, a member of its
Executive Committee, its Metaprise Project, and the KMCI Institute Governing
Council. Joe is a frequent speaker at national conferences on KM and Portals.
He is also developer of the Web site www.dkms.com, one of the most widely visited
Web sites in the Portal and KM fields. DKMS.com has now reached a visitation
rate of 83,000 visits annually.
Executive Information Systems Inc
The Executive Information Systems (EIS) Enterprise Knowledge Portal (EKP) is
the only portal solution that provides the assurance that enterprise decision
making will be based on validated knowledge. EIS’s EKP lets enterprises avoid
the risk involved in Enterprise Information Portals which claim to offer
increases in competitive advantage, ROI, speed of innovation, productivity,
effectiveness and profitability, but have as a central vulnerability the fact
that they are only capable of managing data and information, not
knowledge.
Enterprises using EIP-based solutions when they could be using EKP-based ones,
are gambling that unvalidated information can produce promised EIP benefits.
The central value proposition of the EIS EKP is that it replaces gambling on
unvalidated information with knowledge-based decision making. That is why it
is much more likely to achieve the promised benefits of EIP-based solutions
than its EIP competitors.
For more information, see
www.dkms.com
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