Trial Types

The type column is the only required column in every trial file. It determines how Testable treats each row.

type is also where a project forks into its two worlds. Four values make experiment trials: test, practice, learn, and instructions. The fifth, form, makes a survey row, a single question rendered on a survey page. Everything else in the trial file builds on this choice: experiment trials present stimuli and collect timed responses, while form rows present questions and collect answers.

The fork is per row, not per project. One trial file can mix both kinds freely, questionnaires between task blocks, a scored quiz after a learning phase, or a full experiment bracketed by intake and debrief questions.

Where to go from here:

• Building experiment trials: the Building Experiments pages, starting with Instructions Trials, Define and Position Stimuli, and Responses in Experiments
• Building survey rows: Forms and Surveys
• Combining the two in one file: Mixing Surveys and Experiments

The sections below cover what each type value does.

Caution

Type values are case-sensitive and must be written exactly as documented: Test or TEST silently disables saving, and the trial leaves no results row. The same goes for an empty or unrecognised value: the trial still renders, but nothing is scored or saved. There is no implicit defaulting to test; saving requires the literal value test in the cell. The trial file editor’s dropdown also offers a break value, which has no runtime behaviour (breaks are configured in Project Flow and Trial Management).

test

A standard experimental trial. Testable:

• Presents the stimuli defined in the row
• Accepts the responses you have configured
• Records the participant’s response, reaction time, and correctness
• Saves the result to the participant’s results file

Use test trials for any trial where you want data recorded and accuracy/RT measured.

practice

A practice trial. Behaves identically to test in terms of what is shown and how responses are accepted, but a practice trial writes no results row at all: nothing from it appears in the results file. Responses are still checked against key and counted towards a separate practice accuracy, which is what drives feedback on practice trials.

Use practice to give participants a feel for the task before the real experiment begins. Feedback is fully supported in practice trials.

learn

A study phase trial, used in memory or learning paradigms. Testable presents the stimulus content for participants to study; the response window never opens, so no responses are collected, and the trial auto-advances when its presTime elapses or its media finishes. Like practice, a learn trial writes no results row.

instructions

An instructions screen. Testable displays the text defined in the title and content columns (or the stim column for simple text). Participants read the instructions and click a button (or press a key) to continue.

Use the title column for a heading and the content column for the body text. Both support basic HTML.

type       | title                   | content
instructions | Welcome to the study  | Please respond as quickly and accurately as possible...

Tip

You can also use the stim column on instructions trials to display images, HTML content, or formatted text as the instructions body.

form

A survey question. Each form row is a single question in a survey. Use the head column for the question text and the body column for optional descriptive text below it. The responseType column determines what kind of answer widget is shown (text box, radio buttons, Likert scale, slider, etc.).

Multiple form rows are presented together on the same survey page by default. Use pageBreak to split them across pages.

See Forms and Surveys for full details.

Combining types in one project

A single project can contain multiple types, and often does. A common structure might be:

1. instructions: welcome screen
2. form: demographics questionnaire (several rows)
3. instructions: task instructions
4. practice: a few practice trials
5. test: the main task
6. instructions: debrief / thank you screen