Data: Content, Group, & Behavior

Author: Brett D. Roads

For the purpose of modeling human behavior, data can be conceptualized as having three pieces: the content of the trial, the group membership of the participant, and the participant’s observed behavior. The content and observed behavior depends on the trial type.

The psiz.data module provides lightweight classes that act as an optional on-ramp for users. The module provides the content classes psiz.data.Rate and psiz.data.Rank.

Rank

In the simplest case, an observation is obtained from a trial consisting of three stimuli: a query stimulus ( $q$ ) and two reference stimuli ( $a$ and $b$ ). An agent selects the reference stimulus that they believe is more similar to the query stimulus. For this simple trial, there are only two possible outcomes: either reference $a$ or $b$ is selected.

Rank trials composed of one query and two reference stimuli, are sometimes referred to as triplet trials. In addition to simple triplet trials, PsiZ can handle a number of different rank trial configurations.

Some common rank trial configurations:

2-rank-1: Participant saw three images where one image was a query and the other two images were references. Participants selected the reference they considered most similarity to the query. There are two possible outcomes.

8-rank-2: Participant saw nine images where one image was a query and the other eight images were references. Participants selected the two reference they considered most similarity to the query and also indicated the order (rank) of their selections. There are 56 possible outcomes.

Rate

In the simplest case, an observation is obtained from a trial consisting of two stimuli. An agent provides a numerical rating regarding the similarity between the stimuli.

Other trial types

While rankings and ratings include a large body of research, many other trial types are possible.