Non-experimental designs 2 Flashcards
(14 cards)
Single subject designs
To study a unique individual
Data on only one person (many observations) or differences across individuals
ABAB Reversal Design
Single subject design
A. Measure baseline performance on DV over time (baseline)
B. Administer treatment (IV) and record DV over time
A. Withdraw treatment (reversal), and record DV over time (back to baseline)
B. Administer treatment again and record DV over time
Control for
- history
- maturation
- testing
Multiple Baseline Design
Single subject design
Can be used if treatment creates irreversible change
Attempt to replicate treatment effect by examining several related behaviors in series
Ex- therapy for improving speech articulation for various sounds
Caution for using single-subject designs
Cannot counterbalance treatments
Cannot discern small effects
Cannot generalize to other individuals
Survey research
Relies on self-reports of behavior
Gathers info from sample, to generalize to pop
-> critical to select representative sample
Provides correlational data only!
Selecting samples (for survey research)
Convenience sample
- easy to give questionnaire to
- may be biased, unrepresentative
Random sample
- everyone in pop has equal likelihood of being sampled
- must identify every individual in pop
Stratified sample
- Identify subpopulations (strata)
- select from strata, in proportion to number in population
- > can employ multiple strata (gender, income, race, etc.)
Surveys are
Instruments of communication, not just measures of behavior
- communication involves inferring what is intended by statement/questions
- Respondents infer our intentions from phrasing of survey questions or response choices
Constructing questionnaires
Open-ended questions
-no constraints on responses
Close-ended questions
- provide alternative responses
- helps respondents understand what info is important
- multiple choice
- rating scale
Info respondents use to interpret questions (infer questioner’s intent)
- Response alternatives
- the expected response (close-ended) may not reflect how respondent feels (open-ended) - Values of rating scales
- 0-10 single dimension (0 success)
- -5-+5 bipolar dimension (# of failures; # successes) - Frequency ranges
- must estimate response- assumes middle range is average - Context question
- letter head
- question order (specific -> general)
Guidelines for writing questions
Use interviews to “think aloud” protocols during questionnaire pretesting (check understanding of question)
Request frequency info in open-ended format
Avoid loaded or leading questions
Present conditional information FIRST (because begin to form response before finish reading)
Admin survey by: Mail
Adv.
- no interviewer bias
- contact distant people
- anonymity -> honesty?
Dis
- low response rate
- nonresponse bias
Admin survey by: Phone
Avd
- follow-up questions
- better response rate
Dis
- interviewer bias
- brief questions only
- nonresponse bias
- distractions
Admin survey by: Face to face interview
Adv
- natural way to provide info
- high response rate
Dis
- interviewer bias
- expensive
- loss of anonymity
- sample may not be representative
Admin survey by: Internet
Adv
- fast
- cheap
- contact distant people
- high response rate
Dis
- sample uncontrolled
- may be biased