Final Flashcards
Matching Techniques
- Holding Variables Constant
(i. e. hold gender constant by testing females only) - Build Extraneous Variables into research theme
(i. e. test both genders)
- create a second (non-manipulated) IV
- “statistical control” for some quantitative variables - Yoked Control Procedure
- each control subject “yoked” to an experimental subject - Equating Participants (Best, if possible)
- matches subjects on the variable to be controlled
Disadvantages of Equating Participants Technique
- Difficult to determine which variables are most critical
- Difficulty of finding “matched” participants increases as number of matching variables increases
- Such matching decreases generalizability
- Some variables very difficult to match participants on
Counter balancing
- Randomized
- Complete
- Incomplete
- Intra-subject
One Group Designs
-weak
- Posttest-only Design
- Pretest-Posttest Design
- Nonequivalent Comparison Group Design
Postest-only Design
X O
X is the treatment or the IV
O is the observation of changes in the DV
No control condition to know if the IV affects DV or if effects were caused by some other variable
Pretest-Postest Design
O X O
Observed change in DV from pretest to posttest to see if IV has an effect on DV
Could be several alternative explanations
-Products of “threats to internal validity”
Nonequivalent Comparison Group Design
-common
Posttest only Pretest-Postest test
Experiment X O O X O
Comparison O O O
- not RA
- often self-selected groups
- problem of selection differences
Experimental Group Designs
-strong
- Within-Participants Designs
- Factorial Designs
- Between-Participants Control Group Designs
Within-Participants Designs
- Characteristics
- “Repeated measures” over time
- All subjects receive all conditions
- Fewer subjects
Disadvantages:
- taxing on subjects
- sequencing effect problems
Factorial Designs
2+ IVs, at least 1 is more manipulated
Between-Participants Control Group Designs
Posttest only Pretest-Postest test
Experiment X O O X O
Control O O O
- RA
- Advantages and disadvantages of pretest
Survey Questions
- open-ended
- -hard to score
- closed-ended
- yes/no
- ranking
- rating
- Likert/intensity scale formats
- semantic differential format
- -better to have no ticks in the middle
- -ex. |————————————–|
What is used to evaluate behavioral items of a survey?
Frequency
Surveys Parts
- title and seal
- appeal and instructions
- -short and easy as possible
- headings and subheadings
- transitions
- -few
- response directions
- bold typeface
- justification of response spaces
- shading
- white space
- printing
- font type
Look for normal distribution of answers to determine validity of questions
- differential weighting
- -reported via histogram
Pretesting surveys purposes
- Identify sources of error
- Examine effectiveness of revisions
- changes should be piloted with a different group (naive subjects) - Indicate the effect of alternate versions
- Assess the final version of a questionnaire for respondent understanding, time, and ease of completion
- . Allow the survey analysts to make changes to the format that might make data entry or analysis more efficient
Methods for pretesting surveys
- One-on-one interviews
- Respondent focus groups
- Behavior coding respondent-interviewer interactions
- Interviewer and respondent debriefings
- Item non-response rate
- question skipped a lot? less valid
Administering the survey
- Selecting appropriate respondents
- is the sample representative of the population?
- sample should OVERSTATE the diversity - Choosing a sample size
- Distribute the survey
- standardization
Probability sampling -simple -systematic (ex. exit polling) -stratified -cluster Non-probability sampling -convenience --often used with probability sampling
Coding, Entering, and Analyzing Survey Data
Process includes:
- coding the survey questions
- entering data into spreadsheet
- -2 people
- verifying data are entered correctly
- -random checks of a sample of questions
- conducting statistic analysis
- -t-test
- ANOVA
- interpreting the results
Trend/marginal effect
Called this if not statistically significant but is between 0.05 and 0.10.
Statistical Analysis and Interpretation
- response rate
- reliability
- sampling error
- uni-variate analyses
- -frequency counts, means, modes, medians
- bi-variate and multivariate analyses
- -ANOVA
- -i.e. correlation coefficients, chi-square, t-tests
Presenting surveys
Reporting results to:
- those who commissioned the survey (told at the beginning)
- academic journals
- conferences, colloquiums
- the public at large
Survey Reliability and Validity
Survey reliability
- consistent data
- 2 types of error:
1. Random error - unpredictable
2. Measurement error - associated with how a survey performs in a particular population - -highest in construct validity
Survey validity
- accurate validity
1. Face - pilot subject
2. Content - in survey
3. Criterion-related - predictive (ex. retest in future)
4. Construct
The Survey Research Method
- Specific and measurable
- Straightforward
- Pretested to ensure no unclear questions or incorrect skip patterns
- Administered to adequate population or sample of respondents so generalizations can be made
- Appropriate analysis to obtain objectives
- Accurate reporting of results (verbal and results)
- commissioners - Reliable and Valid
Simple-Subject Designs
- statistics not required (rare)
- one subject or small group of subjects
- “Time-series” designs
- data analyzed via visual inspection
- methods of experimental control involve how the IV is exposed and withdrawn over time
- comparison = subject’s pre-treatment responses
- Baseline (the alpha condition)
- ABA and ABAB designs