IA Objectives

IB Psychology 12
Experimental Design
 Define the aim of a study
 State a research and null hypothesis of a study
 State the independent and dependent variables in an experiment
 State operational definitions of variables
 Describe potential confounding variables
 Explain the controls needed for an experiment (for example, maturation,
contamination, placebo effect)
 Explain effects of participant and researcher expectations and bias
(including demand characteristics, expectancy effect, observer bias)
 Explain the use of single and double-blind techniques
 Discuss the strengths and limitations of experimental designs (for
example, independent samples, repeated measures, matched pairs,
single participant)
Sampling Procedures
 Discuss sampling techniques appropriate to quantitative research (for
example, random opportunity, systematic, stratified)
 Discuss how participants are allocated to experimental and control
groups (for example, matched pairs, random allocation)
 Explain the concept of representative sampling
Evaluation of Research
 Discuss the concepts of internal and external validity
 Discuss conditions that increase a study’s reliability
 Apply descriptive statistics to analyze data (for example, mean, median,
mode, range, standard deviation)
 Distinguish between levels of measurement (including nominal, ordinal,
interval, ratio)
 Apply appropriate graphing techniques to represent data (for example,
bar chart, histogram, line graph)
 Apply an appropriately chosen statistical test (for example, Wicoxon
matched-pairs signed-ranks test, Mann-Whitney U test, sign test, chisquared test) in order to determine the level of significance of data