🗓️Unit 2 Research Methods

PSYC 181 – Intro to Psych

Emma Marshall – Instructor

University of Nebraska-Lincoln

July 17, 2024

What you will learn

Learning Objectives

1. Explain how scientific research addresses questions about behavior
2. Discuss how scientific research guides public policy
3. Appreciate how scientific research can be important in making personal decisions

What is science?

Science has Four Goals

Description

Prediction

Control

Explanation

Psychology as Science

Why is research important?

#NotALLResearch

Can findings be replicated?

Psychologists are ALL scientists

BUT they all approach similar topics differently

The scientific method is circular

Research is an ongoing process…

Theory ↕️ Empirical Data

Theory vs. Hypothesis

Theory

Proposed Explanation

Relies on related concepts to Explain and Predict future events or explain how a phenomenon works

Hypothesis

If-Then Statement

A specific prediction about the relationship between two ideas

Theory or Hypothesis?

A good theory is…

1. Falsifiable
   • Can be shown to be incorrect
2. Empirical
   • Supported by data
   • More supporting data = more confidence
3. Parsimonious

Parisimonious = simple

Evaluating Quality of a Theory

Dessert Preferences & Personality

PICK ONE

Lewandowski (2010)

Present the class with the cover story and dessert options. After they have had enough time to consider their choice, reveal the personality descriptions. Ask students if the description is mostly accurate or inaccurate. Next, ask them if any other desserts would have been accurate. Discuss reasons why this may be the case. Ask students if this makes it hard to know if the prediction was “right”? This is a good time to introduce the problem of vague statements, the Barnum effect, and the need for making testable/specific statements.

The last dessert choice (Pie) can be shown to point out that in the context of these personality descriptions, the general statements work and seem believable because they are positive. If the feedback were negative it becomes less credible.

Dessert Preferences & Personality

• Chocolate Cake
• Strawberry Shortcake
• Flan
• Brownies
• Fruit Pie
• Chocolate Chip Cookies
• Ice Cream
• Mochi
• Frozen Yogurt

Smooth, sexy, & articulate with your hands, you are an excellent after-dinner speaker and a good teacher. But don’t try to walk and chew gum at the same time. A bit of a diva at times, but you have many friends.

Romantic, warm, loving. You care about other people, can be counted on in a pinch and expect the same in return. Intuitively keen. You can be very emotional. You are a friend for life! But look out if someone screws you over. You can hold a grudge.

You are adventurous, love new ideas, and are a champion of underdogs and a slayer of dragons. When tempers flare up you whip out your saber. You are always the oddball with a unique sense of humor and direction. You tend to be very loyal.

You like sports, whether it be baseball, football, basketball, or soccer. If you could, you would like to participate, but you enjoy watching sports. You don’t like to give up the remote control. You tend to be self-centered and high maintenance.

You are a terrible person. No one likes you. Sure, a few people act as if they like you, but they only hang out with you to make fun of you. Turns out, you aren’t that attractive either. Stay in college as long as you can because no one would hire you anyway. Your magic number is…let’s be honest….you have no magic in your life. That makes your magic number zero. Loser.

Sexy; always ready to give and receive. Very creative, adventurous, ambitious, and passionate. You can appear to have a cold exterior but are warm on the inside. Not afraid to take chances. You will not settle for anything average in life. Love to laugh.

You are a very fun loving person, who likes to laugh. You are fun to be with. People like to hang out with you. You are a very warm hearted person and a little quirky at times. You have many loyal friends.

Fun-loving, sassy, humorous, not very grounded in life; very indecisive and lack motivation.

Everyone enjoys being around you, but you are a practical joker. Others should be cautious in making you mad. However, you are a friend for life.

Sweet, loving, cuddly. You love all warm and fuzzy items. A little nutty at times. Sometimes

you need an ice cream cone at the end of the day. Others perceive you as being childlike and immature at times.

Lewandowski (2010)

What is the problem with this Dessert Personality theory?

What types of studies are used in psychological research?

Approaches to research

Three types of studies

1. Descriptive
2. Correlational
3. Experimental

Variables

A variable is…

• any concept or property that can be measured and changed
• Each type of research provides different amounts of control over variables

Changing Variables

Researchers change variables in two ways

• Manipulate: change or control within study
• Measure: evaluate or assess within study

Measuring Variables

Study Type 1: Descriptive Research

Descriptive Research

Systematically and objectively observing psychological phenomenon to describe what, when, how it occurs

Note: Researchers do not control phenomenon

Descriptive Research

Types of descriptive studies

Case Studies

• Examine one subject in detail
• Cannot apply to others

Observational Studies

• Systematic recording of behaviors
• Participant vs. Naturalistic

Self-Reports

• Surveys or Interviews
• Asking about themselves
• Can provide more specific information

Descriptive Example

Study Type 2: Correlational Research

Correlational Research

Data is from:

• Archives or records
• Observations
• Surveys or Interviews

Examine how variables are related in the world without attempts to control the variables

Correlation refers to a linear statistical relationship

Correlational Research: Example

What is the relationship between Superman’s height and age?

Correlation does not equal causation

Third Variable Problem

Another confounding variable might explain the relationship between the variables

Note: Correlational designs are incomplete for explaining most psychological phenomenon

Why conduct correlational research?

If cannot measure relationships otherwise…

Ethical considerations

Technological limitations

Cannot manipulate variables of interest

Research Ethics

I was A Guard in the 1971 Stanford Prison Experiment. AMA!

Study Type 3: Experimental Research

Experimental methods control and explain.

Designing an experiment

• Enable scientists to have maximum control
• Independent variable (IV)
• Dependent variable (DV)
• Confounding variable(s)
  • Any other variables

Independent variable is manipulated

Experimental/treatment group

• Participants who receive the treatment of interest
• Control/Comparison group
• Participants who DO NOT receive the treatment of interest

Participants need to be selected carefully…

Sampling is the process of selecting a group of individuals to participate in study

Sample should represent the population

And randomly assigned to an IV condition

Random assignment controls for confounding variables

Random Assignment Needed for Causal Interpretation!

Allows researchers to assume

• Individual differences are evenly distributed between conditions
• All differences between the conditions are due to the treatment

Interpreting Results

Monty Hall Study

Our Class Data

N=34 out of 50 Students Responded

Summary Statistics

Metric	StayGames	StayWins	SwitchGames	SwitchWins	StayProbability	SwitchProbability	Age
Min.	0.000	0.000	0.000	0.000	0.0000	0.0000	18.00
1st Qu.	1.000	0.000	0.000	0.000	0.0000	0.6333	19.00
Median	1.000	1.000	1.000	1.000	0.5000	1.0000	20.00
Mean	3.324	1.378	2.081	1.486	0.4628	0.7774	19.86
3rd Qu.	3.000	1.000	3.000	2.000	1.0000	1.0000	20.00
Max.	28.000	13.000	10.000	7.000	1.0000	1.0000	24.00
NA's	NA	NA	NA	NA	4	14	NA

Monty Hall Performance

Relationship between Age and Performance?

How can I interpret these findings?

Was this an experiment?

• Sampling?
• Independent variable (IV)?
• Dependent variable (DV)?
• Confounding variable(s)?

Our Class vs. Pigeons

Studies find that Pigeons outperform humans on this task

Herbranson & Schroeder (2010)

In the field of comparative psychology, the cognitive abilities of humans and non-human animals are compared. How do humans compare to pigeons and monkeys when solving the Monty Hall puzzler? Unencumbered by faulty heuristics, pigeons do better than humans in solving the game. Pigeons played an operant version of the game with the chance to win mixed grain as the prize and with many opportunities to play. Although pigeons, like many college students, began with a tendency to stay with their first selection, the pigeons quickly and efficiently learned that the optimal strategy was to switch on every trial (Herbranson & Schroeder, 2010).

#NotALLResearch