Microgenetic Designs Designed to answer questions about how learning occurs

1. Microgenetic Designs • Designed to answer questions about how learning occurs

2. Three “essential” characteristics: • Observations are made across a period of rapidly changing competence in a particular area • Within this period, the density of observations is high relative to the rate of change • Observations are analyzed intensively to infer underlying processes

3. Microgenetic studies typically involve: • Relatively small numbers of participants (or single subject designs) • Trial-by-trial assessments of children’s strategies for solving particular types of problems • Behavioral observations of strategy use (often supplemented with self-reports in children 5 years and older)

4. Overlapping Waves Theory (R. S. Siegler) • Microgenetic studies across different areas consistently indicate that children’s thinking is highly variable • For example: • Different children use different strategies • Individual children use different strategies on different problems within a single test session • Individual children use different strategies to solve the same problem on two occasions close in time

5. According to Overlapping Waves Theory: • Development is a process of variability, choice, and change • Children typically know and use varied strategies for solving a given problem at any one time • With age and experience: • Relative frequency of existing strategies changes • New strategies are discovered • Some older strategies are abandoned

6. Children usually choose adaptively among strategies • Choose strategies that fit the demands of the problem given the strategies and available knowledge that children possess • Choices of strategies become even more adaptive with experience in a particular content area

7. According to OWT, cognitive change can be analyzed along five dimensions • Source of change (causes that set the change in motion) • Path of change (sequence of knowledge states or predominant behaviors that children use while gaining competence) • Rate of change (how much time or experience separates initial use of a new strategy from consistent use of it) • Breadth of change (how widely the new strategy is generalized to other problems and contexts) • Variability of change (differences among children in the other dimensions of change; changing set of strategies used by individual children)

8. Siegler (1995) • Examined effects of training on strategy use for number conservation problems (N=45; 54-73 mos., mean = 5.17 years) • Could add more buttons and make one line a different length; could take away buttons and make one line a different length; or could change the length of the line and not add or take away any buttons • Random assignment to one of three training conditions • Feedback only (answer correct/incorrect) • Feedback plus explain-own-reasoning (“How did you know that?” followed by feedback) • Feedback plus explain-experimenter’s reasoning (Feedback followed by “How do you think I knew that?”)

9. Findings • Different Types of Strategies (Explanations) Used: • Relative Length: Compare lengths of two rows • Type of Transformation: Objects added/subtracted or just moved around • Counting • “Don’t know”

10. Over the course of the experiment: • Frequency of length strategies decreased • Frequency of transformation strategies increased • Frequency of counting remained consistently low • “I don’t know” first increased and then decreased