Welcome to Research Methods and Experimentation

How do psychologists collect data about behavior?

 Regardless of the method used, all research is based on the Scientific Method of Psychology  Scientific means systematic, testable, and objective.

What are the three main principles that guide the Scientific Method of Psychology? What are the three main principles that guide the Scientific Method of Psychology?

Scientific Method  Step 1 – Theory  Step 2 – Hypotheses  Step 3 – Research and Observation

 Theories organize known facts and summarizes current research in the field.

 A hypothesis is then created as a testable prediction based on what is currently known and what we want to find out.

 Research or observation or experiments are generated to collect data, which then goes into evaluating the hypothesis, which may or may not add to the existing theory.

What are the most common methods used by psychologists to collect data?

Naturalistic Observation

 Study behavior in in a subject’s natural environment.  No interaction with the subject. Is this natural?

What are some potential problems with this type of research? What are some potential problems with this type of research?

Bias  Situation in which a factor unfairly increases the likelihood of a researcher reaching a particular conclusion

Example of Bias I am researching teenagers behavior and I was recently mugged by a group of teenagers… am I likely to observe teenage behaviors as being motivated by evil versus good? I am researching teenagers behavior and I was recently mugged by a group of teenagers… am I likely to observe teenage behaviors as being motivated by evil versus good?Why?

Let’s try this out !!!

Going for an “observational” walk  We are going to walk through the building  Your job is to write EVERY behavior you see…  When we come back to the room, ask yourself “Why was ____ doing ____?”  Please do not communicate with anyone during this exercise !!!!

Case Studies

Case Study  In depth study of one individual with the hopes of determining universal principles  Very open to bias  Difficulty of applying data from one person to everyone

Case Study  Case studies often include face-to-face interviews, paper and pencil tests, and more.

 IE. I want to know why Bart killed thirty-five people over a twenty-year period of time. I will examine the police files, observe and interview Bart, talk to his and the victims families, etc.

Difficulty of applying data from one person to everyone bias, etc What are some potential problems with this type of research? What are some potential problems with this type of research?

Surveys

Survey Method  Research method that relies on self-reports; uses questionnaires, interviews.  Usually a very efficient and inexpensive method to collect a lot of information and create basic assumptions about behaviors.

…very tricky to make a good survey!  Questions need precise answers  Wording must be simple: 77% of New Yorkers interested in plants and trees, but only 39% interested in botany;  Don’t embarrass or humiliate  Responders will lie if there is a perceived punishment  To long  Etc…  Can you spot the problems….?

Correlation

Correlational Study  Research study designed to determine the degree to which two variables are related to one another

 IE. What is the relationship between exercise and weight? Smoking and cancer? Brain size and intelligence? Education and level of income?

Is there a correlation?

What are some potential problems with this type of research? What are some potential problems with this type of research?

 Watch out for illusory correlations!  Does sugar make kids more hyper?  Does a full moon make people act crazier?  Does going outside with no coat on mean you will catch a cold?

Correlational Study  Correlation studies DO NOT prove causation. They can only suggest that there is or is not a relationship between the two variables.

 IE. A correlation study may suggest that people who earn higher levels of education generally earn higher salaries, but it can’t definitively say that getting a degree will get you a higher paying job. A correlation study may suggest that people who earn higher levels of education generally earn higher salaries, but it can’t definitively say that getting a degree will get you a higher paying job.

Graphing Correlation Relationships

 After you plot the data the slope (direction) of the line indicates whether or not there is a positive, negative, or no relationship between variables.  How close the dots are together indicates how close the relationship between the variables is.

Positive Correlation  As the value of one variable increases (or decreases) so does the value of the other variable.

 Studying and Grades As students study more, their grades increase.As students study more, their grades increase.  Practice and Athletics As athletes practice more, their batting averages increaseAs athletes practice more, their batting averages increase  Dieting and Weight Loss As dieters ate less, their weight dropped.As dieters ate less, their weight dropped.

Negative Correlation  As the value of one variable increases, the value of the other variable decreases. The more you exercise, the less you weighThe more you exercise, the less you weigh The more you study, the less your teachers yell at youThe more you study, the less your teachers yell at you

Zero Correlation  There is no relationship whatsoever between the two variables. The length of your hair has no influence on your level of intelligence.The length of your hair has no influence on your level of intelligence.

Correlational Study  Important NOT to imply a cause and effect relationship between the variables  Correlational study does not determine why the two variables are related--just that they are related.  Correlational studies are helpful in making predictions.

Experiment

Experiment  An investigation seeking to understand relations of cause and effect.

 IE. I want to know if new drug A will help to alleviate the symptoms of insomnia. Patients will be given different doses at different times to see what works and what doesn’t. I need to control other factors, like mattress softness and room temperature, to eliminate them as causes of sleep deprivation.

How do I create a valid and reliable experiment? How do I create a valid and reliable experiment?

 The Hawthorne Effect refers to the fact that some subjects will alter their behaviors simply because they know that they are part of an experiment, regardless of what is being done to them.

Step 1: Choose a Hypothesis Hypothesis expresses a perceived relationship between two variables. IE. My hypothesis is that watching violent television shows makes people more aggressive.IE. My hypothesis is that watching violent television shows makes people more aggressive.

Step 2: Choose Variables  Variables are things that are measured, controlled, or manipulated in research.

 The independent variable is the manipulated variable.  IE. Watching television violence is the independent variable because I can adjust what shows are viewed, for how long, by whom, etc.

 The dependent variable is measured for change.  IE. Measuring the change in aggression levels is the dependent variable in our experiment because it changes based on what is viewed, for how long, etc.

Step 3: Identify Extraneous/Confounding Variables  Any factor that can effect an experiment (other than the variable being studied) is considered an extraneous variable.

 IE. An extraneous variable in our experiment would be a phone call from a solicitor during a program that might make the viewer angry, the viewer receiving mail including a poor report card, a viewer stubbing their toe during a show, alcohol abuse, etc. All of these could increase aggressiveness, but are not related to viewing violent television.

Step 4: Identify Who You Will Be Testing  The individuals on which the research will be conducted are called subjects.  A small group of subjects are drawn from a larger potential population.

 IE. Our subjects will be drawn from the overall population of 12 th grade students at Appoquinimink High School.

Step 5: How Do We Decide Who Will Be Subjects, and Who Won’t?  Since we can’t realistically include all 12 th graders at AHS in our study, we have to somehow narrow down the population to more manageable numbers. But how?

Method 1: Rigorous Control Design  Designing an experiment with specific, hand-picked groups in mind. IE. Only testing males, 18 years old, in CP Psychology.

Method 2: Sample Design  A random sample allows that every member of an overall population has an equal chance to be in the sample. IE. Drawing names from a hat. IE. Drawing names from a hat.

Step Six: Assignment  Once you have chosen your subjects to study, you must assign them to one of two groups; those that will be manipulated, and those that won’t.

Group 1: Experimental Group  The experimental group receives the independent variable and is manipulated throughout the experiment.

 IE. In our television violence experiment, those in the experiment group will watch varying degrees of violent program, for varying lengths of time, etc., and their changes in levels of aggression measured.

Group 2: Control Group  The control group does not receive the independent variable.

 IE. In our television violence experiment, the control group will be shown a variety of non-violent programming in order to create a baseline to compare the experiment group against.

Blind Procedure  An experimental procedure where the research participants are ignorant (blind) to the expected outcome of the experiment  Sometimes called single blind procedure

Double Blind Procedure  An experimental procedure where both the research participants and those collecting the data are ignorant (blind) to the expected outcome of the experiment

Step 7: Replication  Repeating the experiment to determine if similar results are found  If so, the research is considered reliable.