experimental research design and methodology in tpr

Experimental research design and methodology in TPR

PhD Course in Translation Process ResearchCopenhagen, July 2014

Outline Research design – basic concepts Experimental tools and methods to

collect translation process data Examples of experimental TPR studies Some practical considerations about

carrying out experiments

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Design Starting point: I-wonder-question Rephrase as research question/hypothesisConsider What type of question/hypothesis it is Sample and population Which variables are involved

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Design: Research question/hypothesis

Formulate your I-wonder-question clearly and unambiguously

Make it falsifiable Consider whether your starting point is

Question: Is there a difference between students and professional translators in terms of ST reading?

Open hypothesis: There is a difference between students and professionals in terms of ST reading

Directional hypothesis: There is a difference between students and professional translators in terms of ST reading, such that professionals spend less time on the ST 6


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Design: Type of question/hypothesis

Differences Repeated measures: measuring effect of some

difference within one group, e.g. same translators working under different conditions or

over a period of time (longitudinal study) Independent groups: group difference between

different groups doing same task, e.g. students vs. professionals training vs. control group

Functional relations Between response and some manipulated variable

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Design: Sampling and population

Inferential statistics assumes random sampling

In practice, balance between randomness and possibility

Consider population and sample Which population does my question pertain to? Is it realistic to sample from that population? Could a realistic sample pertain to a different,

but still relevant population?10


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Design: Variables

Two important distinctions Independent/explanatory (EV),

dependent (DV) and control (CV) variables

Categorical and numerical variables

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Design: DVs Dependent/response variable (DV): what you

are measuring or counting, e.g. Translation time

Overall Individual fixations

Translation quality Number of occurrences of e.g.

metaphors specific syntactic constructions …

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Design: EVs Independent/explanatory variables (EVs):

Variables which according to your hypothesis may have an effect on your DV

Also called predictors Types

Item-related: e.g. task difficulty, translation direction, translation tool

Participant-related: e.g. sex/gender, L1, professional status, L2 experience

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Design: CVs Control variables (CVs): variables to

control in order to be sure that EV is responsible for DV Experimental control Statistical control

Avoid confounds15

Design: Categorical and numerical variables

Categorical Unordered categories (nominal): e.g. sex/gender, word

class Ordered categories (ordinal): e.g. lower/middle/upper class

Numerical Discrete

Integers, finite values E.g. counts of word in a corpus

Continuous Real numbers, infinitely many values on scale E.g. reading time

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Design: Categorical and numerical variablesTranslation experience may be construed as Nominal scale: student/professional Ordinal scale: beginning / advanced

student / professional Discrete numerical: number of years of

experience (1, 2, 3, 4…) Continuous numerical: amount of

experience (time, output)17

Design: Categorical and numerical variablesImportant ramifications for

The questions asked

The type of statistical test to be applied

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Experimental TPR tools and methods

eye-tracking keylogging audio recording (in Translog) (video recording) (think-aloud protocols) retrospective interviews and

questionnaires

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Eye-tracking eye-mind assumption (Just and Carpenter 1980) cogntive attention cognitive load areas of interest (AOI) eye-tracking measures

fixation count total gaze time fixation duration pupil dilation eye movements (transitions, attention shifts)

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Keylogging

transient versions of target text revision/editing navigation pauses production speed final target texts

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Audio recording (available in Translog) oral translations think-aloud comments

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Questionnaires/retrospective interviews language background professional background perception of source text difficulty perception of different tasks translation challenges experienced etc.

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Assessing the product translation quality assessments examination of translation of individual

words (e.g. metaphors, terminology, specific word classes, number of alternative translation solutions, etc.)

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Example 1: The Process of Post-Editing:

a Pilot Study

Example 1: goal to find out (‘I wonder’) how translators,

with no post-editing training, would perform when asked to post-edit MT-produced output in comparison with the performance of a group of translators who translated the same texts manually, without any dictionary or technical assistance.

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Example 1: research questions what are the differences in quality between

manual translations and post-edited MT output? do more corrections lead to higher quality in the

post-edited texts? what are the time differences between manual

translations and post-editing? what are the differences in allocation of

cognitive resources between manual translation and post-editing

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Example 1: design/set-up experimental research design with

manipulation of circumstances to measure the effect on participants’ behaviour

lab environment simulating natural conditions translation rankings

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Example 1: variables Dependent/response variables

translation time translation quality allocation of cognitive resources (ST vs. TT)

Independent/explanatory variable translation mode (manual translation vs.

post-editing)

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Example 1: variables control variables

using the same participants with the same text for both tasks might have created an unintended repetition effect

using the same participants but different texts might have created an unintended effect of textual differences (e.g. one text more difficult than the other)

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Example 1: experiments Modes

manual translation and post-editing Participants

8 translators and 7 post-editors Texts

three English source texts (same for both groups)

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Example 1: experiments one group of participants translated

three texts (from scratch) from English into Danish and

one group of participants post-edited machine-translated (Google Translate) Danish versions of the the same three source texts

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Example 1: tools/methods eye-tracking

allocation of cognitive resources (total gaze time on ST vs. TT)

keyloggingtask timekeystrokes (edit distance)final output

translation evaluationstranslation quality

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Example 1: quality assessment QA method and procedure

7 evaluators presentation of source sentence together with four

candidate translations two sentences had been produced using manual translation

and two had been produced using post-editing (randomised and blinded)

evaluators were instructed to rank candidate translations from best to worst quality (ties permitted).

inter-rater and intra-rater agreement did evaluators agree with each other were evaluators consistents in their rankings

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Example 1: design weaknesses sample size participant qualifications (not all worked as

professional translators) quality assessments (assessment task too

difficult, inter-rater and intra-rater agreement too low)

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Example 2: Speaking your translation

students’ first encounter with speech recognition technology

Example 2: goal to measure the impact on the translation

process and product of using an automatic speech recognition (ASR) system compared with typing a translation and producing a sight translation without ASR

to measure the effect of training/practice with ASR on task time and quality of translations produced with ASR

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Example 2: research questions (quantitative) What are the task times in the three

translation modalities (written, sight, ASR)? Is there any difference in translation quality in

the three modalities? Is there any difference in cognitive load? What is the effect on time and quality of

participants training the system and gaining more experience using it?

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Example 2: research questions(qualitative) What are the students’ own perception of

working with an ASR system? What kind of strategies are employed by

students who experience positive effects on time and quality?

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Example 2: design/set-up experimental research design with manipulation of

circumstances to measure the effect on participants’ behaviour

lab environment analysis of process and product longitudinal study experimental group compared with control group qualitative analyses

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Example 2: variables Dependent/response variables

translation time translation quality cognitive load (average fixation durations)

Independent/explanatory variables translation mode (written, sight, ASR) training period

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Example 2: variables Control variables

texts had to be as similar as possible to ensure that process/product differences across translation tasks were caused by the mode and not by the text

sequence of presentation was rotated to ensure that differences between the written and oral modalities were owing to the translation mode and not, for instance, to varying levels of difficulty

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Example 2: experiments participants

14 translation students divided into two groups of seven: an experimental (training) group and a control group

modes written translation sight translation sight translation with speech recognition

text text excerpts taken from the same longer text to

ensure the highest possible level of similarity48

Example 2: experiments Longitudinal study:

phase 1 (baseline): all participants translated texts under three different conditions

interim period: half of the participants (experimental group) worked with the ASR program at home (partly under controlled conditions) and the other half did not (control group)

phase 2 (follow-up): all participants translated texts under three different conditions (similar to phase 1), and results from experimental group were compared with control group and related to phase 1

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Example 2: tools/methods eye-tracking

cognitive load (fixation duration) Translog

timingsoral and written outputtransient versions of oral and written translations

evaluations of translation outputtranslation quality

retrospective interviewsstudents’ perceptions of ASR vs. written/sight

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Example 2: quality assessment QA method and procedure

3 evaluators each evaluator assessed all three texts for all 14

participants (blinded with respect to mode) global scores were given on a scale from 1-5 comments were provided to back up scores

inter-rater agreement did evaluators agree with each other

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Example 2: retrospective interviews

All participants: general impression of using ASR benefits and drawbacks/problems

Experimental group (training group) total training time type of texts produced using ASR general impression problems encountered

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Example 2: case studies small samples weaken the validity of

quantitative results large individual differences between

translators (individual translator profiles) in-depth analyses are extremely time-

consuming identification of participants who confirm

(reject) the hypothesis detailed analysis of strategies, gaze and

keystroke patterns, choice of words etc. 53

Example 2: design weaknesses ecological validity

unfamiliar setting too little control during training period

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Setting up the experiment make detailed description (’protocol’) of

experiment, including every action that needs to be carried out

write instruction for participants (so that they all receive the same information)

run pilot(s)

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Running the experiment increase eye-tracking data quality by

calibrating subjects before each new session

optimising light conditions (no direct sunlight)

checking distance to screen check settings in Translog check audio quality if using audio

recordings57

experimental research design and methodology in tpr

Documents

populationwhich variables

experimental research

group difference

involved44designstarting

st66designstarting point

starting point isquestion

different groups

professional translators