Problem Solving Tasks
tasks. Its main difference to game is that it does not create
trials on the fly but each single task has to exactly correspond to a
single trial. The problems involved my have some internal step-like
structure but the single steps are not resolved by prob. Currently
there are only 2 types of problems available: anagram rearrangement and
An anagram is a string anagram of characters which have to be rearranged in
order to convert the string into a word. Rearrangement is done by
sequentially pointing to a single character of the test string with the mouse
cursor and press a mouse button. The character then is transfered from
the test string to the next free position of the solution string answer.
Pointing to a character in the solution string moves the character back
to its original position in the test string. The trial is considered to
be finished by prob if all characters of the test string have been
moved to the solution string. The program may check for correct
solutions by comparing the solution string with the string parameter
word and setting eval accordingly.
A labyrinth is defined by a series of connected straight line segments. Each
labyrinth is contained in a file whose name is defined by labfile.
The labyrinth files are searched in the directory given by
labdir. A single line in the file contains points of a single
polygon which have to be
connected. Each new line starts a new polygon. The single polygon points
are given as xy-coordinate pairs. Before drawing the polygons its
coordinates are transformed such that the wole labyrinth is centered on
the screen. Labyrinth size is controlled by labunit which gives the
number of PXL drawing units (pxlm) for each unit of the labyrinth
coordinates in the file. Figure lab shows an example
of a labyrinth file and its corresponding labyrinth.
In addition to the polygon points the first line in the
file contains the start and the end position for the problem.
Each labyrinth may contain up to maxpolygons polygons and each
single polygon may contain up to maxppoints points.
Insert Figure lab here.
The subject starts with the mouse pointing to the start position.
Imagine an extensible rubber string connected to the mouse pointer. The
string may be fixed to a given position by pressing the left mouse
button. Initially the string is fixed only to the start position. The
subject has to move through the labyrint and fix the string such that it
never contacts any of the labyrinth walls. The trial is finished if the
string is fixed near the end position.
Faked Solution Time
During each session the program computes the average solution time for
the single problems. This time is stored in timeaverage. This time
may be fed back to the subject by messages between trials or blocks. The
feedback messages may be biased by using faketime instead of
timeaverage. The actual value of faketime is timeaverage
multiplied by fakefactor.
Response Evaluation and Feedback
The parameter eval contains the result of the response evaluation.
According to this result the feedback message may be one of the
following string parameters: corrmsg, falsemsg,
timeoutmsg, or illegalmsg. The default is feedbackmsg.
The feedback message is shown for feedbacktime ms.
- foreground (int)
- Foreground objects drawing color.
- background (int)
- Background color.
- msgcolor (int)
- Text message color.
- question (string)
- Question between trials. If this string is nonzero
then it will be asked as a question between trials.
- qresponse (int)
- Response to question.
- task (int)
- Type of problem to solve:
- ANAGRAM (1)
- Anagram task.
- LABYRINTH (2)
- Labyrinth task.
- estimatemsg (string)
- Message text that requests an estimate of the solution
- fakefactor (float)
- Fake feedback time factor.
- faketime (float)
- Fake average solution time.
- flags (string)
- These flags are available:
- Present a request for the expected solution time from the
subject before starting a trial. The requesting message is estimatemsg and
the response is stored in response.
- Ask for a motivation scale value before starting a trial. The
question asked is question and the response is stored in qresponse.
The response is collected by presenting a rating scale on the screen and
allowing the subject to select a position on the scale.
- If this flag is set then the rubber string may not be fixed at
any arbitrary position but is restricted to positions exactly between
the labyrinth walls. The point automatically snaps on to the grid of
- timeaverage (float)
- Correct average solution time until now.
- timeunit (int)
- Timing unit in ms. Most time values for prob are not
given in milliseconds but in units of timeunit milliseconds. This
affects: dsptime, rtime, and all values derived from these
like timeaverage and faketime.
- waitclear (int)
- Waiting time before clear screen.
Anagram Task Parameters
- anagram (string)
- Anagram string.
- word (string)
- Solution word.
- rowdist (int)
- Vertical baseline distance of anagram and solution word.
- coldis (int)
- Horizontal character distance.
Labyrinth Task Parameters
- startcolor (int)
- Starting point mark color.
- trackcolor (int)
- Tracking rubber band color.
- finishcolor (int)
- Goal point mark color.
- labcolor (int)
- Labyrinth wall color.
- labfilepath (string)
- Name of the directory where to find the labyrinth files.
- labunit (int)
- Labyrinth coordinates unit size in pxlm.
- labfile (string)
- Labyrinth file name.
- maxpolygons (int)
- Maximum number of polygons in any single labyrinth.
- maxppoints (int)
- Maximum number of points per polygon found in any labyrinth.
- maxtrackpoints (int)
- Maximum number tracking points allowed.
- intersections (int)
- Number of intersections of the tracking line with the
labyrinth walls generated by a subject's path.
This is an example of the anagram task.
Parameter file anagram.x from directory \pxl\app\prob
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