Single-Factor Within-Groups Design

Single-Factor Within-Groups Design

ADVANTAGES

DISADVANTAGES

Equivalent groups

Requires fewer participants

Special populations

Only way for some research questions

(Increased power)

(Efficient use of resources)

2 Ways of Measuring the DV

Concurrent-Measures Design

Repeated-Measures Design

Will participants figure out your hypothesis?

Attrition (repeated measures)

Order effects

Progressive effects

Carryover effects

Types of Counterbalancing

Complete Counterbalancing

Latin Square

Random-selected-orders

Cancels out order effects

Less complex; don't need as many participants

Practicality

N! orders

Possibility of carry-over effects

Possible order effects

<3 (or 4) conditions

3/+ conditions

Large N

EXPOSED TO LEVELS OF IV ONCE

EXPOSED TO LEVELS OF IV TWICE+

Block Randomization

Reverse Counterbalancing

Practicality

Not as effective as ABBA for linear effects

More effective for linear order effects

Assumes linearity

Definitely linear order effects

Non-linear or unknown pattern of order effects

Demand characteristics

ADVANTAGE

DISADVANTAGE

When to Use