System and method for identifying conditions leading to a particular result in a multi-variant system

An apparatus for constructing an induction tree having a plurality of nodes which is for use in determining a cause of a particular result of a process from a data set including values for each of a first plurality of attributes arising during each of a second plurality of runs of the process and an indication of a class associated with each of the second plurality of runs, wherein the runs during which the particular result occurred are in a first class and the runs during which the particular result did not occur are in a second class, comprising:

• data entry means for permitting a user to enter the data set;
• a memory for storing the data set;
• a processing unit including,
• means for dividing the values within the data set and associated with each of the first plurality of attributes into value groups at each of a third plurality of the nodes, wherein a class heuristic defining an expected distribution of classes among value groups of a certain one of the attributes is identified and wherein the dividing means includes means for determining whether an actual distribution of classes among the value groups of the certain one of the attributes is consistent with the class heuristic,
• means coupled to the dividing means for allowing a user to select one of the first plurality of attributes at each of the third plurality of the nodes,
• means coupled to the allowing means for designating one of the value groups of the selected attribute as an endpoint of the induction tree when the one of the value groups satisfies an endpoint criterion and, otherwise, designating the one of the value groups of the selected attribute as a branching point of the induction tree, wherein the value group designated as a branching point contains a certain number of values associated with a certain number of runs, and
• means coupled to the designating means and to the dividing means and operable when a value group of the selected attribute has been designated as a branching point for redefining the data set to include the values associated with the certain number of runs, and
• an output device which develops a representation of the induction tree for the user.

A method of forcing a repetitively-executed process toward a particular outcome, comprising the steps of:

• determining attributes which potentially affect the outcome;
• collecting attribute data indicative of each attribute during a number of prior runs of the process;
• obtaining outcome data indicative of the outcome of each prior process run;
• building an induction tree from the collected attribute data and the obtained outcome data including dividing the attribute data into value groups and determining whether an actual distribution of outcomes associated with the attribute data in the value groups of a certain one of the attributes is consistent with a class heuristic defining an expected distribution of outcomes among the attribute data of the values groups of the certain one of the attributes;
• finding a path in the induction tree which indicates that the particular outcome is more likely to occur than not;
• and
• using the found path to specify attribute values for a subsequent run of the process.

A method of determining a cause of a particular result of a process from values each associated with one of a first plurality of attributes arising during each of a second plurality of runs of the process, comprising the steps of:

• (a) defining a data set to include the plurality of values;
• (b) dividing the values associated with each of the first plurality of attributes within the data set into value groups wherein the values associated with a certain one of the attributes are in a continuum and the step of dividing includes the steps of;
• (1) grouping the runs during which the particular result occurred into a first class and grouping the runs during which the particular result did not occur into a second class,
• (2) dividing the continuum into a set of ranges wherein each value group associated with the certain one of the attributes includes the values within one of the ranges including the steps of;
• (i) dividing the values associated with the certain one of the attributes into first and second sets according to the classes of the runs during which the values arose,
• (ii) determining a statistical property of the first set,
• (iii) determining a statistical property of the second set,
• (iv) developing first and second subsets of values from the first and second sets wherein the first subset includes the values of the first set which are greater than the statistical property of the first set and the second subset includes the values of the second set which are less than the statistical property of the second set,
• (v) determining a statistical property of the first subset,
• (vi) determining a statistical property of the second subset,
• (vii) replacing the statistical properties of the first and second sets with the statistical properties of the first and second subsets, respectively, if the statistical property of the first subset is less than the statistical property of the second subset,
• (viii) repeating the steps (iv) through (vii) until the statistical property of the first subset is greater than or equal to the statistical property of the second subset, and
• (ix) defining a first range having a region below the statistical property of the first set, a second range having a region between the statistical property of the first set and the statistical property of the second set and a third range having a region above the statistical property of the second set;
• (c) allowing a user to select one of the attributes;
• (d) designating a value group of the selected attribute as an endpoint of an induction tree when the value group satisfies an endpoint criterion and, otherwise, designating the value group of the selected attribute as a branching point of the induction tree, wherein the value group designated as a branching point contains a certain number of values which are associated with a certain number of runs;
• (e) redefining the data set to include only the values associated with the certain number of runs;
• (f) repeating steps (b) through (e) until a value group is designated as an endpoint in step (d);
• and
• (g) identifying one or more of the value groups designated as one of the endpoints and the value groups designated as branching points within a path to one of the endpoints as a cause of the particular result.

A method of controlling the incidence of a particular result which arises during a run of a process using values each associated with one of a first plurality of attributes arising during each of a second plurality of runs of the process, wherein the values associated with one of the attributes fall within a continuum, and wherein a certain number of runs are grouped into a plurality of classes based on the occurrence of the particular result within each of the certain number of runs, comprising the steps of:

• (A) constructing an induction tree from the plurality of values including the steps of,
• (a) dividing the values associated with the one of the attributes into first and second sets according to the classes of the runs during which the values arose,
• (b) determining a statistical property of the first set,
• (c) determining a statistical property of the second set, and
• (d) dividing the values associated with the one of the attributes into ranges defined in accordance with the statistical properties of the first and second sets including the steps of,
• (i) developing first and second subsets of values from the first and second sets wherein the first subset includes the values of the first set which are greater than the statistical property of the first set and the second subset includes the values of the second set which are less than the statistical property of the second set,
• (ii) determining a statistical property of the first subset,
• (iii) determining a statistical property of the second subset,
• (iv) replacing the statistical properties of the first and second sets with the statistical properties of the first and second subsets, respectively, if the statistical property of the first subset is less than the statistical property of the second subset,
• (v) repeating the steps (i) through (iv) until the statistical property of the first subset is greater than or equal to the statistical property of the second subset, and
• (vi) defining a first range having a region below the statistical property of the first set, a second range having a region between the statistical property of the first set and the statistical property of the second set and a third range having a region above the statistical property of the second set;
• (B) determining a cause of the particular result from the induction tree;
• and
• (C) controlling a run of the process in accordance with the determined cause to either reduce or increase the probability of incidence of the particular result.

A method of controlling the incidence of a particular result which arises during a run of a process using a plurality of values each associated with one of a first plurality of attributes arising during each of a second plurality of runs of the process, wherein a class heuristic which defines an expected distribution of classes among value groups of a certain one of the attributes is identified, comprising the steps of:

• (a) defining a data set to include the plurality of values;
• (b) dividing the values within the data set and which are associated with each of the attributes into value groups;
• (c) comparing an actual distribution of classes among value groups of the certain one of the attributes with the class heuristic;
• (d) selecting one of the attributes based on the step of comparing;
• (e) designating one of the value groups of the selected attribute as an endpoint when an endpoint criterion is satisfied and, otherwise, designating the one of the value groups of the selected attribute as a branching point, wherein a value group designated as a branching point contains a certain number of values associated with a certain number of runs;
• (f) redefining the data set to include only the values associated with the certain number of runs;
• (g) repeating steps (b) through (f) until a value group is designated as an endpoint in step (e);
• (i) identifying one of the value groups designated as the endpoint and the value groups designated as branching points within a path to the endpoint as a cause of the particular result;
• and
• (j) controlling a run of the process in accordance with the identified cause to either reduce or increase the probability of incidence of the particular result.

A system for use in developing an indication of a cause of a particular result of a process from values each associated with one of a first plurality of attributes arising during an associated one of a second plurality of runs of the process, wherein the runs during which the particular result occurred are in a first class and the runs during which the particular result did not occur are in a second class, comprising:

• data entry means for permitting a user to enter data indicating the attribute values and the class associated with each of the second plurality of runs;
• a memory for storing the data indicating the plurality of attribute values and the class associated with each of the second plurality of runs;
• a processing unit including,
• means for dividing the values associated with each of the attributes into value groups wherein the values associated with a particular one of the attributes are in a continuum and wherein the dividing means divides the continuum into a set of ranges such that each value group associated with the particular one of the attributes includes the values within one of the ranges, the dividing means including;
• (1) means for separating the values of the particular one of the attributes into first and second sets according to the classes of the runs during which the values arose,
• (2) first means for measuring a statistical property of the first set,
• (3) second means for measuring a statistical property of the second set, and
• (4) means for developing the set of ranges from the statistical properties of the first and second sets including (a) means for deriving first and second subsets of values from the first and second sets wherein the first subset includes the values of the first set which are greater than the statistical property of the first set and the second subset includes the values of the second set which are less than the statistical property of the second set, (b) means for finding a statistical property of the first and second subsets, (c) means coupled to the deriving means for replacing the statistical properties of the first and second sets with the statistical properties of the first and second subsets, respectively, if the statistical property of the first subset is less than the statistical property of the second subset and (d) means coupled to the deriving means and operable when the statistical property of the first subset is greater than or equal to the statistical property of the second subset for defining a first range having a region below the statistical property of the first set, a second range having a region between the statistical property of the first set and the statistical property of the second set and a third range having a region above the statistical property of the second set,
• means for selecting any one of the first plurality of attributes,
• means for designating a value group of the selected attribute as an endpoint of an induction tree when the value group satisfies an endpoint criteria and, otherwise, designating the value group of the selected attribute as a branching point of the induction tree,
• means operative when a value group of the selected attribute is designated as a branching point for redividing the values associated with attributes other than the selected attribute into further value groups,
• means operative when a value group of the selected attribute is designated as a branching point and coupled to the redividing means for choosing a further attribute, and
• further means coupled to the choosing means for determining whether any further value group of the further attribute satisfies the endpoint criterion and thus comprises an endpoint of the induction tree;
• and
• an output device which develops a representation of the induction tree for the user.