Importing data

In Psifr, free recall data are imported in the form of a “long” format table. Each row corresponds to one study or recall event. Study events include any time an item was presented to the participant. Recall events correspond to any recall attempt; this includes repeats of items there were already recalled and intrusions of items that were not present in the study list.

This type of information is well represented in a CSV spreadsheet, though any file format supported by pandas may be used for input. To import from a CSV, use pandas.read_csv(). For example:

import pandas as pd
data = pd.read_csv("my_data.csv")

Trial information

The basic information that must be included for each event is the following:

subject

Some code (numeric or string) indicating individual participants. Must be unique for a given experiment. For example, sub-101.

list

Numeric code indicating individual lists. Must be unique within subject.

trial_type

String indicating whether each event is a study event or a recall event.

position

Integer indicating position within a given phase of the list. For study events, this corresponds to input position (also referred to as serial position). For recall events, this corresponds to output position.

item

Individual thing being recalled, such as a word. May be specified with text (e.g., pumpkin, Jack Nicholson) or a numeric code (682, 121). Either way, the text or number must be unique to that item. Text is easier to read and does not require any additional information for interpretation and is therefore preferred if available.

Example

Sample data

subject	list	trial_type	position	item
1	1	study	1	absence
1	1	study	2	hollow
1	1	study	3	pupil
1	1	recall	1	pupil
1	1	recall	2	absence

Additional information

Additional fields may be included in the data to indicate other aspects of the experiment, such as presentation time, stimulus category, experimental session, distraction length, etc. All of these fields can then be used for analysis in Psifr.