The Scientific Method and Description Module 5 The Scientific Method and Description

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)

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

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)

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.

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.

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

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