Module 5

1. Module 5 The Scientific Method and Description

2. Scientific Method • Theory – an explanation using an integrated set of principles that organizes observations and predicts behaviors or events. • Hypothesis– a testable prediction often implied by a theory • Theory – ADHD/sugar link • Hypothesis: If a kid eats sugar, the kid will act more impulsive, distracted, and hyper • Null hypothesis – the statement that the independent variable will have no effect on the dependent variable (assumed correct until we can encounter scientific evidence to reject it)

3. Scientific Method • Operational definition – statements of the procedures used to define research variables • Determines how we measure the variables • ADHD Ex. - Impulsivity = # of times/hour calling out without raising hand • Allows for replication of study • Eliminates experimenter bias • Replication – repeating a research study usually with different participants in different situations to see whether the basic finding extends to other participants and circumstances

4. Testing and refining theories • Descriptive methods – describe behavior • Case studies, naturalistic observations, surveys/interviews • Correlational methods – associates/link certain factors (relationship between variables) • Experimental methods – manipulate variables to discover their effects (cause and effect)

5. Descriptive Research Methods • Case study – A descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles • Opportunity for insights that one could/would never attempt to gain through designing an experiment (ex) brain injuries, Genie • But: must be careful not to generalize, individual cases may be atypical • Naturalistic Observation - Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.

6. Research Methods • Survey - A technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group • Wording effect - the results you get from a survey can be changed by your word selection. • (ex.) Do you have motivation to study hard for this course? • (ex.) Do you feel a desire to study hard for this course? • Only question randomly sampled people • Subject to dishonesty and sampling bias.

7. Populations and Samples • Population (target population)– all those in a group being studied, from which samples may be drawn. • Random sample - a sample that fairly represents a population because each member has an equal chance of inclusion. • The larger the sample the more accurate the study • Stratified sample – subgroups in the population are represented proportionally in the sample • Sampling bias – a flawed sampling that produces an unrepresentative sample • Subject bias – having more knowledge and interest in what is being studied • Volunteer bias – people who volunteer are different from people who don’t volunteer

8. Other Methods of Research • Laboratory Observation – studying behavior in a controlled situation/environment • Benefit of controlling the environment but not natural • Ultimately – general principles revealed help explain everyday behavior • Longitudinal Method – studying the same people over a long period of time • Can accurately study changes over time but people may drop out and it is time consuming • Cross-sectional Method – studying different age groups at the same time in order to understand changes that occur during the lifespan • Less time-consuming but not as accurate – variable of differing generations