Scientific Method & Descriptive Research Methods Module 5

Goals of Psychology Describe – Objectively describe the different ways that organisms behave Explain – Explain the Cause of the Behavior? Why? Predict – Predict how organisms will behave in certain situations Control – Control an organism’s behavior or change it Don’t Eat Purple Cheese!

Scientific Method

Theory Tentative explanation for observed findings Organizes results from accumulation of highly researched, rigorously tested findings from individual studies Leads to hypothesis/predictions which leads to research Reflects self-correcting nature of scientific method. Good way to think about a Theory: – Prosecuting Attorney presents their theory backed up by evidence to the jury.

Hypothesis A testable prediction derived from a theory. Explains what the researcher is trying to find out "If {these changes are made to a certain independent variable}, then we will observe {a change in a specific dependent variable}." Checklist: Does your hypothesis focus on something that you can actually test? Does your hypothesis include both an independent and dependent variable? Can you manipulate the variables? Can your hypothesis be tested without violating ethical standards? Examples: "Students who eat breakfast will perform better on a math exam than students who do not eat breakfast." "Students who experience test anxiety prior to an English exam will get higher scores than students who do not experience test anxiety."

Operational Definitions How will you observe & measure the behavior you are studying? – Must be objective and able to be repeated by others – Must reduce a behavior to a number for statistical analysis How would you operationally define… – Happiness – Popularity – A Smile – Intelligence

Replication For a study to be valid, it must be… Replicated/Repeated with different people in different situations to determine if the results from the original study are correct Only then can results be generalized (applied to most people)

Why is Research Important? Method of asking questions then drawing logical supported conclusions Researchers need to be able to determine if conclusions are reasonable or not (critical thinking). Does this seem like a Reasonable conclusion?

Descriptive Studies Descriptive—strategies for observing and describing behavior (answer who, what, when, where & how often) – Case studies – Naturalistic observation – Surveys – Correlational methods These do NOT Show Cause and Effect

Case Study In depth study of one individual with the hopes of determining universal principles Difficulty of applying data from one person to everyone Generally used to investigate rare, unusual, or extreme conditions

Naturalistic Observation Method of observation where subjects are observed in their “natural” environment Subjects are not aware they are being watched Could use hidden cameras or two way mirrors Only describes behavior, NOT explain it.

Enemy to Naturalistic Observation: Participant Bias/ Hawthorne Effect Tendency of research subjects to respond in certain ways because they know they are being observed The subjects might try to behave in ways they believe the researcher wants them to behave Subject can’t know they’re being watched or they’ll change their behavior! Named after Hawthorne Works study on productivity where every variable looked at (levels of light, listening to music) increased worker productivity? Why?

Survey Method Research method that relies on self-reports to find out attitudes and behaviors of a particular group. Usually a very efficient and inexpensive method Be careful what we take from polling information: 20 Questions to Ask About Poll/Survey Results Watch out for Framing/Wording Effects – The way a question is worded can bias the answer.

Framing & Wording Effects How you ask the question matters! You must ask it in a neutral way. How you ask the question matters! You must ask it in a neutral way. One survey found that 77% were interested in plants and trees but only 39% were interested in botany. Let’s say you work for the Centers for Disease Control and there is an outbreak of a deadly disease called “The Mojave Flu” in a town of 600 people. All 600 people in the town are expected to die if you do nothing. Let’s say you have come up with two different programs designed to fight to the disease: With Program 1: 200 people in the town will be saved With Program 2: There is a 1/3rd probability that 600 people will be saved, and a 2/3rds probability that no people will be saved. In the study, 72% of the subjects picked Program 1. Now consider the same scenario worded differently: With Program 3: 400 people in the town will die With Program 4: There is a 1/3rd probability that nobody will die, and a 2/3rds probability that 600 people will die. Now which do you pick? In the study, 78% of the subjects picked Program 4, even though the net result of the second set of choices is exactly the same as the first set (Programs 1 and 3 mean the same thing, and Programs 2 and 4 mean the same thing).

SamplingTerms Population—large (potentially infinite) group represented by the sample. Findings are generalized to this group. Sample—selected segment of the population Random selection—every member of larger group has equal chance of being selected for the study sample Random selection Random Sample – Results from random selection, each member of the population had an equal chance of being included. – If a sample is not random it is said to be biased. Representative/Stratified sample—closely parallels the population on relevant characteristics – Your goal is to get a representative sample and avoid sampling bias – unrepresentative sample that can’t be generalized on the rest of the population. Watch this short clip on the difference between these. (3 min)