Lecture+18+-+2.24.25+-+Within-groups+designs

Page 1

Overview

  • The page contains grading classifications: Excellent, Very Good, Good, Average, Poor.

  • Mention of a product taste testing link.

Page 2

Summary of Elements

  • Reiteration of grading classifications.

  • Mention of taste testing, similar to Page 1.

  • Link provided for product taste testing solutions.

Page 3

Recap of Relevant Content

  • No significant new content compared to previous pages.

Page 4

Consistency in Content

  • Continues the theme with similar content as previous pages including grading levels and the taste testing link.

Page 5

Important Reminders

  • Midterm grades will be available by Friday.

  • Quiz 7 submission due before midnight.

  • The final exam will be online, focusing on material since the second exam but with cumulative themes.

Page 6

Between and Within-groups Designs

  • Discusses various designs in experiments.

  • Topics include extraneous variables, confounds, instrumentation effects, and participant treatment.

  • Advantages/disadvantages of within-subjects designs are mentioned.

Page 7

Controlled Experiments: Between-groups

  • Definition of between-groups (also known as between-subjects or independent-groups).

  • Essential requirements: equivalence of groups and absence of confounds are highlighted.

  • Impacts on causal inference.

Page 8

Extraneous Variables Control Strategies

  • Discusses methods to control extraneous variables to avoid bias.

  • Introduces single-blind and double-blind procedures.

Page 9

Treatment of Groups

  • Emphasis on uniformity in treatment across experimental groups.

  • Importance of matching conditions to avoid introducing confounds.

Page 10

Instrumentation Effects

  • Discusses variations in measurement accuracy over time and their impact on results.

Page 11

Participant Attrition

  • Outlines systematic and non-systematic attrition from studies and their implications.

Page 12

Sensitivity of Dependent Variables

  • Highlights the importance of having sensitive measures to detect changes and the potential for Type II errors.

Page 13

Determining Sensitivity in Measures

  • Discussion of ceiling and floor effects in measuring dependent variables.

Page 14

Between-groups Advantages and Disadvantages

  • Lists benefits such as straightforward causal effects and comparisons.

  • Discusses downsides for requiring additional participant groups and potential for variances.

Page 15

Example of Controlled Experiments

  • Identifies the population and sample sizes used in a between-groups design.

Page 16

Within-groups Designs

  • Definitions and characteristics of within-subjects designs.

  • Notes the minimized error variability and participant requirements.

Page 17

Reducing Variability

  • Discusses implications of individual differences on variability in group comparisons.

Page 18

Understanding Variability Impacts

  • Continues the discussion of the significance of reducing individual differences for error reduction.

Page 19

Group Comparisons in Research

  • Analysis of variances between and within groups indicating controlled experiments aim to lower error variance.

Page 20

Effect Detection Probability

  • Clarifies that as error variance drops, the likelihood of detecting a real effect rises.

Page 21

Types of Within-subjects Designs

  • Introduces pretest-posttest and repeated-measures designs, outlining their characteristics.

Page 22

Simple Pretest-Posttest Design

  • Discusses a basic therapeutic study design relevant to measuring performance before and after intervention.

Page 23

Measuring Effects in Studies

  • Same design as previous; highlights reading program effectiveness measurement before/after treatment.

Page 24

Repeated Measures in Studies

  • Explanation of participants going through all conditions and collecting varied measures.

Page 25

Historical Context: Stroop Experiment

  • Discusses the Stroop effect as a classic example of independent and dependent variables involved in cognitive research.

Page 26

Detailed Example of Repeated Measures

  • Reiterate the ability to take multiple measurements from same participants across conditions.

Page 27

Similar Content Focus

  • Reiteration of repeated measures within individual participants to understand effects thoroughly.

Page 28

Combining Designs

  • Introduces cross-over design which integrates both within and between-groups designs for comparison.

Page 29

Clinical Trial Design Choices

  • Proposal of various experimental designs and the implications of the design choice for drug trials.

Page 30

Considerations for Drug Trials

  • Highlights potential design preferences for comparing new and existing treatments.

Page 31

Within-subjects Design Challenges

  • Discusses the potential complexities that arise from having participants involved in all independent variable conditions.

Page 32

Demand Characteristics as a Problem

  • Elaborates on how repeated exposure to stimuli may influence participant behavior and possible strategies to mitigate this.

Page 33

Carryover Effects Issues

  • Highlights practice and fatigue effects as key concerns needing careful management in experimental design.

Page 34

Patterns of Practice Effects

  • Discusses linear and non-linear practice effects and the necessity for counterbalancing.

Page 35

Time-related Confounds

  • Mentions potential external events that may influence participant performance over the course of the study.

Page 36

Study Example of Motivation's Effect

  • Scenario provided to analyze how time delays between tests may introduce potential confounds.

Page 37

Confounding Variables in Research Study

  • Discussion of how timing between tests may affect outcomes due to external factors.

Page 38

Reaction Time Study Example

  • Analyzes how individual learning curves can introduce practice effects in reaction time studies.

Page 39

Importance of Specific Task Performance

  • Clarification of how task-specific learning impacts the interpretation of study outcomes.

Page 40

Strategies for Counterbalancing

  • Discusses counterbalancing as a method to control for order effects while conducting experiments.

Page 41

Trial Requirements and Considerations

  • Emphasizes the impact of trial designs on measurement sensitivity and statistical power.

Page 42

Block Trials Discussion

  • Definition of block trials and their role in organizing experimental conditions effectively.

Page 43

Factors in Ordering Trials

  • Key considerations for the time taken by trials and their implications on participant fatigue or maturation effects.

Page 44

Complete Counterbalancing Examples

  • Provides an example illustrating how to use various counterbalancing techniques to control for biases in experimental conditions.