A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Absent - a feature may be present or absent in an artifact or assemblage. Using the feature parameters Earlier, Later, Blanks and Zeroes, a user may indicate when blank data or a zero should be considered as indicating the absence of a feature. See Setting the Earlier, Later, Blanks, Zeroes and Transition Parameters.
Active - a parameter that allows the user to specify the data set and seriation to use.
Artifact - an object being seriated (ordered). See Artifacts.
Assemblage - a collection of artifacts. See Assemblages.
Blank - values in the data may be blank. See Blanks and Zeroes.
Blanks - a feature parameter that lets the user tell OptiPath how to interpret blanks in the data (as zeroes, as absences or as unknowns). See Blanks, Blanks and Zeroes and Setting the Earlier, Later, Blanks, Zeroes and Transition Parameters.
Classed Data - alphanumeric values ("red", "-78", "large", "3.14159", "0", "absent", "dentate", etc.) that represent classifications of feature values. The feature parameter Data can be used to specify that a feature should use Classed Data.
Custom Seriation - a seriation technique that is determined by the user by selecting parameter settings used to specify Seriation techniques and Feature parameters. See Custom Seriation.
Data - values or measurements associated with the features for each artifact or assemblage. See Data.
Data Parameter - a feature parameter that lets the user tell OptiPath how to interpret the input data (as Measured, Ranked or Classed). See Data.
Data Set - a collection of artifacts or assemblages which the user is trying to seriate. See Data Sets.
Discrete Seriation - a seriation technique that is a special case of shortest path seriation where the feature values happen to be integral. See Discrete Seriation.
Distance - a measure of how much the features of one artifact differ from another. Distance is measured according to a distance function, or metric (Euclidean, Manhattan or Hamming). See Distances.
Distance Function - a metric for computing distance (Euclidean, Manhattan or Hamming).
Earlier - a feature parameter that lets the user tell OptiPath what assumptions to make about artifacts earlier than those in the data set. See Earlier, Earlier and Later and Setting the Earlier, Later, Blanks, Zeroes and Transition Parameters.
Earliest - a parameter that lets the user tell OptiPath the earliest allowable date for artifacts. An earliest date for all artifacts and assemblages can be set in the Seriations table; earliest dates for individual artifacts can be set in the Artifacts and Assemblages tables.
Euclidean Distance - a distance function (metric) where the distance between two items (artifacts or assemblages) is the square root of the sum of the squared differences in all of the dimensions (features) in which the items differ. Compare with Hamming distance and Manhattan distance. See Euclidean Distance.
Exclude - a parameter that lets the user tell OptiPath exclude artifacts, assemblages or features from the current seriation without removing them permanently from the data.
Excel - Microsoft Excel. OptiPath supports importing a data table from a Microsoft Excel spreadsheet and exporting results via a tab delimited text file. See Import andExport.
Export - to export a data set and seriation from OptiPath to an external data format. OptiPath supports exporting a data set to a tab delimited text file which is readily imported by database and spreadsheet programs. See Export.
Features - Features are measurable attributes shared by artifacts. It is usually assumed in seriation that the evolution of a feature's measure over time is unimodal and/or gradual. See Features.
Files - the permanent database files retained on your computer even when OptiPath is not running. A file holds all of the data for your data sets and seriations. See Files.
Frequency Seriation - a seriation technique that is a special case of optimal path seriation where assemblages are treated as artifacts. See Frequency Seriation.
Hamming Distance - a distace function (metric) where the distance between two items (artifacts or assemblages) is the number of dimensions (features) in which the items differ. Compare with Manhattan distance and Euclidean distance distance. See Hamming Distance.
Heuristic - a simplified and approximate method of analyzing a problem (for example, a rule of thumb rather than formal mathematical analysis). Heuristics may not always achieve the optimal outcome, but they are generally much easier to implement than optimal procedures and are generally much faster to execute.
Import - to import data from a source outside of OptiPath. OptiPath supports importing a data set from a Comma Separated Value and from a Microsoft Excel spreadsheet. See Import.
Index - an integer value assigned to an item (artifact or assemblage) that allows users to sort items in a list. The Index of an item can be set in the Artifacts (Assemblages) and Data tables.
Later - a feature parameter that lets the user tell OptiPath what assumptions to make about artifacts later than those in the data set. See Later, Earlier and Later and Setting the Earlier, Later, Blanks, Zeroes and Transition Parameters.
Latest - a seriation parameter that lets the user tell OptiPath the latest allowable date for all artifacts. A latest date for all artifacts can be set in the Seriations table; latest dates for individual artifacts can be set in the Artifacts and Assemblages tables. See Latest.
Manhattan Distance - a distance function (metric) where the distance between two items (artifacts or assemblages) is the sum of the absolute values of the differences in all of the dimensions (features) in which the items differ. Compare with Hamming distance and Euclidean distance. See Manhattan Distance.
Measured Data - numerical values, including integers (-5, 1, 3, 0, etc.) and fractions expressed as decimals (1.3, -0.43, -3.14159, 2.71828, etc.), that represent measurements (or counts) of feature values. The feature parameter Data can be used to specify that a feature should use measured data. See Measured Data.
Metric - a feature parameter that lets the user tell OptiPath which metric, or distance function, (Euclidean, Manhattan or Hamming) to use in computing the feature's contribution to the distance between two items (artifacts or assemblages).
Nominal - establishing an identity rather than an ordinal value or seriable magnitude The feature parameter Data can be used to specify that a feature should use classed data. See Nominal Seriation.
Nominal Seriation - a seriation technique that is a generalization of occurrence seriation. Instead of categorizing each feature into two classes, the technique allows any number of classes. See Nominal Seriation.
Normalize - a feature parameter that lets the user tell OptiPath to normalize the data for the feature. Normalization is done by converting values to standard deviations. See Normalize.
Objective - a function whose value is being optimized in seriating. Objectives include maximizing unimodality and maximizing gradualness of change from one item to the next in a seriation.
Occurrence Seriation - a seriation technique used when only the presence or absence of features is known and measured data is unavailable. See Occurrence Seriation.
Optimal Path Seriation - a mathematically based seriation methodology which considers items to be seriated (artifacts or assemblages) to be defined by the features they have in common. Each feature is considered a dimension and the values of the features for an item determine a point in feature space. A seriation is an ordering of the items which in turn determines a path through these points in feature space. The seriation problem is to find the path that optimizes a given objective. Many objectives have been proposed over the years including unimodularity (battleship shaped curves), uninterrupted occurrence, similarity and gradualness. These objectives have led to differing techniques of seriation including frequency seriation, occurrence seriation, similarity seriation, shortest path seriation and even component analysis. All of them, however, can be considered special cases of optimal path seriation.
Order - an artifact or assemblage's sequential (ordinal) position in a seriation.
Path - each item in a seriation is defined by its feature values which determine a unique point in feature space. A seriation determines a path connecting these points (items) in feature space. The distance from one point to the next in the seriation is a measure of the change in features from one item to the next. The path with the least overall change will be the shortest path through all the points.
Present - a feature may be present or absent in an artifact or assemblage. Using the feature parameters Earlier, Later, Blanks and Zeroes, a user may indicate when blank data or a zero should be considered as indicating the absence of a feature. See Setting the Earlier, Later, Blanks, Zeroes and Transition Parameters.
R2 - the coefficient of determination, a statistical measure of how well a model approximates the data. An R2 of 1 indicates that a model is a perfect fit to the data. The R2 value is an estimate of what fraction of the variance in the data is explained by the model (the variance of the model's errors). R2 = 1 - (the sum over all the data of the squared differences of the actual values of the data and the values predicted by the model) divided by (the sum of the squared differences of the predicted values and the mean of those values).
Randomize - a seriation parameter that lets the user tell OptiPath whether or not to randomize the search for a good seriation when using heuristic solution procedures. Randomizing can lead to better, but not necessarily reproducible, results. Reproducible randomized results can be obtained by setting the Seed. See Randomize.
Ranked Data - integer values (-5, 1, 3, 0, etc.) that represent counts or rankings of feature values. The feature parameter Data can be used to specify that a feature should use ranked data. See Ranked Data.
Ranks - a feature parameter that lets the user tell OptiPath the limit on the number of categories or classes to which a feature can be assigned. See Ranks.
Relations - restrictions that certain artifacts or assemblages must precede others.
Seed - a seriation parameter that lets the user specify a starting point for the random number generator that allows results to be reproduced when using randomized heuristic solution procedures. See Seed.
Seriate - to order or arrange in a series. For archaeologists a seriation is generally an attempt to arrange items (artifacts or Assemblages) in chronological order.
Seriation - an ordering or arrangement of items (artifacts or Assemblages) in a manner to approximate assumed serial patterns in the measures of the items' features. The underlying assumption in archaeological seriation is that a correct chronological ordering of items would exhibit such patterns, in particular that the evolution of a feature is unimodal and/or gradual. Evolutionary gradualness is rooted in the assumption that the form of an artifact is influenced by the form of functionally similar artifacts that preceded it. The implication is that artifacts whose manufacture is proximate in time and space will be of similar form or style. From this the converse is concluded, that artifacts with similar style or form are likely to have origins that are proximate in time and space. Therefore, by considering artifacts’ style and form it is possible to determine a most likely ordering of their origins in time or space. See Seriations.
Shortest Path Seriation - a seriation technique based upon mathematical optimization heuristics. Shortest path seriation relies on the assumption that the artifacts to be seriated share characteristics or features whose measures evolve gradually over time. The ordering of artifacts that produces the most unimodal and/or gradual evolution of all features for all artifacts is considered the optimal seriation. Shortest path seriation was developed by Brett Shepardson and Fred Shepardson and is being documented in a paper to be submitted for publication. See Shortest Path Seriation.
Shuffle - to reorder a seriation randomly. Shuffle is an option on the seriation dialog. See Shuffle.
Table - a standard way of presenting data in OptiPath. Any information entered into a row of a table may not be saved or take effect until the cursor is moved to another row of the table..
Technique - a seriation parameter that allows the user to specify the seriation technique (Shortest Path, Occurrence, Frequency, Discrete, Nominal or Custom) to be used. See Technique.
Transition - given the ordering of a seriation, a particular feature may be absent at first, then present for a while and then absent again. This pattern may be repeated more than once for a feature. The appearance, or disappearance, of the feature in the archaeological record (the seriation) is referred to as a transition. See Transition Penalties.
Transition Penalty - a feature parameter that lets the user tell OptiPath how important it is that a feature appear only once in the archaeological record, rather than appearing multiple times with intervening intervals where the feature is absent. See Transition Penalties.
Unimodality - the mathematical concept that expresses the idea that a style appears in the archaeological record, gains in popularity over time and then loses popularity until it vanishes from the record. See Unimodality.
Unknown - a blank or zero in the data may indicate that the value of the feature for this artifact is unknown. Using the feature parameters Earlier, Later, Blanks and Zeroes, a user may indicate when blank data or a zero should be considered as having an unknown value. See Blanks, Blanks and Zeroes, Earlier and Later and Setting the Earlier, Later, Blanks, Zeroes and Transition Parameters.
Updates - for the latest version of OptiPath visit the OptiPath website.
Values - the input data after it has been interpreted and processed according to the user's feature parameters. See Values..
Weight - a feature parameter that lets the user tell OptiPath how much importance to give a feature relative to other features. See Weight.
Weights - a seriation parameter that lets the user tell OptiPath whether or not to use weights on features while computing distances between artifacts. See Weights.
Zeroes - a feature parameter that lets the user tell OptiPath how to interpret zeroes in the data (as values, as absences, as values and absences, or as unknowns). See Blanks, Blanks and Zeroes and Setting the Earlier, Later, Blanks, Zeroes and Transition Parameters.