pre-workshop session poitiers, july 1 st 2015 pre-workshop session poitiers, july 1 st 2015

Pre-workshop sessionPre-workshop sessionPoitiers, july 1st 2015

Pre-workshop sessionPre-workshop sessionPoitiers, july 1st 2015

1. Data files2. Open a protocol3. Environment and navigation4. Pauses and fixations preview 5. Protocol description6. Eye movement data: fixations, AOI7. Data extraction – part 1

8. words separation and sequences9. Data extraction – part 2

Data analysis

July 1st 2015 Mshs, University of Poitiers, France

1. Data files

.TABContains the original tablet (”pen”) data.

.EYEContains the original eye tracking data (“eye”), if any.

.LOG (script only)Contains mains events recorded within the session.


Log file example


2. Opening a protocol

Start a new analysisMenu “File”, “new analysis”, then select a .TAB file (eye tracking data will be automatically loaded if it exists).

Resume an analysisAfter a first analysis (saved), menu “File”, “re-open”, then select a .TWK file.


Saving a protocol analysis generate new files:

.TWK Tablet data analysis

.EWK Eye tracking data analysis


Let’s open a protocol


3. Environment and navigation

Navigation

tool for coding

Information bar


3. Environment and navigation

ToolbarAllows to replay the protocol (movie-like, pause by pause, etc.) and create sequences.

Information barGives additional informations (distance, speed, duration) on current events and a quick acces to change background picture.

Tool for codingGive information on current Tab and EYE samples (pressure, coordinates, duration). Allows to “attach” a numeric value to each sample (code).e.g.: code 1 for between syllables and code 12 for pauses inside syllable.


Navigation tools

View or “dwell” in the data with several modes.To name a few :

- Protocol replay (tunable replay speed)

-Event by event (samples)

- Pause by pause (e.g., to see inter-word pause duration)

- Using the stopwatch


Navigation tools


4. P review of pauses and fixations

Preview as “circles” Cicle size is proportional to the event duration (pause/fixation).

4.2 Preview as “heatmap”Colors represents events duration (from cold to warm – more than 2 seconds).May be used to adjust eye tracking data location over handwriting.


Preview as “heatmap”


5. Protocol descriptionStatistics

Global information-Pre-writing pause duration-Product duration (without pre-writing)

-Last “up” pause duration

Detailed informations-Durations (in ms)-Distances (in cm)-Speed (in cm/s)


Graphs

Pauses (UP/DOWN) and fixationsDistribution of durations (in ms).

Pen mouvementsSpeed histogram (in cm/s).

Eye mouvementsSpeed histogram (in cm/s).

CaracteristicsInformations on devices used to record protocol (tablet / eyetracker).

5. Protocol description


Create fixations

A fixation is a construction

Define AOI

e.g.: if you create AOI around words, you may extract number of fixation per word, total duration of fixations, etc.

6. Eye movement data: fixations, AOI


Test a massive data extraction: all events -> Gives a huge volume of data to sort (using a spreadsheet or a database)

7. Data extraction – part 1


How can we filter data ?

Question: what is the production duration of words ?

1. Set code “1” to the first TAB sample of the word, set code “2” to the last sample, set code “3” to the first sample of the next word, etc.

1_________2 3___________4 5___________ 6 7___________8

2. Menu Extraction | preferences | codes. set TAB codes to 1-127. Set Eye Codes to 0-127.

3. Select menu Extraction | All events

But This method does not allow to easily extract writing length, pauses inside words, etc. It is much more efficient to isolate words within sequences to get more data.

8. Word separation and sequences

Word separationA semi-automated way to segment tablet data.“Tools”, “Word separation”, “New”…

A sequence is a subpart of a protocol defined by time boundaries.


Stage1: adjust detection parameters Set beginning and end time of the “segment” to consider (default is: whole protocol)

Set horizontal and vertical margins around detected items. Items with ovelapping marings will be merged. Exclude small items ex: dot on “i” Test

Word separation


The process involve two stages

Stage 2: manually modifiy items1- Modify word by word: delete, insert, change time boundaries2- add label(s). ex Grammatical category of each word, typo, etc.

Word separation


Options :- Code first and last TAB sample of each word- Code pauses between words- Create sequences from words- Create AOI from words

Codes values set in File | Configuration | Analysis | Tools

Sequences allows to extract data on specific parts of the protocol.e.g.: tracing dynamics for each word

Word separation


now, saving your analysis may generate new files:

.TWK Tablet data analysis

.EWK Eye tracking data analysis

.HST Analysis history

.SEQ Sequences data

.WDS Words separation data


Set/check data extraction preferences before exporting data

- General: overwrite or append to existing file- Range: whole protocol or only data within sequences-Data: which information to export (time, …)- Codes: filter on code values-Tracing dynamics: detail levels-AOI: grouped by AOI, or in time order

9. Data extraction - part 2


Data extraction

With sequences (Extraction / Preferences / range)

-All events

- pauses

-tracing dynamics without pauses

-tracing dynamics including pauses


Thank you for your attention

pre-workshop session poitiers, july 1 st 2015 pre-workshop session poitiers, july 1 st 2015

Documents

france slide

university of poitiers

protocol analysis

file eye tracking data

data extraction

data files

twktablet data analysis

eye movement data