Chapter 2: Research Methods

Scientific Method

Systematic process involving steps like defining questions, forming hypotheses, conducting experiments, and analyzing data.

Theory

Broad explanation that predicts people’s behavior (s) across situations and over time.

i.e., Generalization about the causes of people's behavior(s).

Which of the following is an example of a theory?

High-sugar diets cause ADHD.

Which statement represents a theory about behavior?

Playing violent video games causes increased aggression in pre-teens.

A researcher wants to test the theory that a high-sugar diet causes hyperactivity. One group of students receives a sugary food or drink, while another group does not. The researcher then observes how much the students talk and interact during class. Which group is the experimental group?

The students who receive the sugary food or drink

Hypothesis

Testable prediction drawn from a theory that describes how the theory will be investigated.

(One sentence that outlines the design of a study and includes expected results of the study)

A researcher wants to test whether sugar affects students’ behavior. Children who consume 100 grams of sugar before class are expected to be more talkative and distracted than children who consume no sugar. What is this an example of?

Hypothesis

A researcher predicts that children age 2 or older will cry longer when their mother leaves than children under age 2. What is this an example of?

Hypothesis

A researcher predicts that pre-teens who play violent video games will show increased aggression compared with pre-teens who do not. What is this an example of?

Hypothesis

Experimentation/Observation/Analyses (Operationalization)

Part of research design describing how you will measure the behaviors that you are investigating in your study 

ex:  Surveys, questionnaires, interviews, observations, psychological tests/ measures

A researcher wants to determine whether a high-sugar diet causes hyperactivity in children. Which method would be most appropriate for measuring the children's hyperactive behavior during class?

Directly observing and recording how often they talk, leave their seats, and become distracted

Replication

To confirm findings, researchers conduct replication studies by repeating experiments across different laboratories and populations to verify that results are consistent and reliable

Hindsight Bias

 Tendency to believe we could have foreseen an event after it has occurred

( I knew it all along/after the fact common sense)

Ex: Tendency to accept findings without critique; not so fast without consequence view of data, and you saw it and accept it because it was by a researcher or had some research article

Overconfidence

Tendency to overestimate the accuracy of our current knowledge. Tendency to be egocentric.

(Our views are most important/correct/valid) (What we think is correct)

After a tennis competition, researchers find that players who practiced for two hours beforehand performed worse because they were tired. A student says, “I knew all along that practicing right before the competition would hurt their performance.” What does this demonstrate?

Hindsight bias

A person says, “I drink alcohol every day, but I know I won’t become an alcoholic because I can handle it.” What does this statement best demonstrate?

Overconfidence

Correlational Research Methods

Use of statistical formulas allowing us to study the degree of relationship between variables in a study.

(Variable= something measured in a study, so sugar and adhd are variables- are they related? More sugar=more adhd

Correlation Coefficient

A statistical measure (numerical value) describe the strength of relationship between variables in a study

• Numerical value can be a number ranging between 1 to -1

• Numbers close to 1 and -1 represent the strongest predictive relationships between variables

• Numbers close to 0 represent the weakest predictive relationship between variables

r = number between 0 and 1, or 0 and -1

A researcher finds a correlation of r = -0.90 between daily screen time and hours of sleep. What does this correlation indicate?

A strong negative relationship

Directionality

Refers to whether two variables change in the same direction or opposite directions, shown by the + or - sign

• Positive correlation (+): As one variable increases, the other also increases.

  • Example: Higher SAT scores → higher college GPAs.

• Negative correlation (-): As one variable increases, the other decreases.

  • Example: Temperature decreases → incidence of colds increases.

+ = together
- = opposite

A researcher finds that as students' hours of sleep increase, their reported fatigue decreases. What is the direction of the correlation?

Negative correlation (-) because one variable increases while the other decreases.

Magnitude

Strength or consistency of the relationship between variables. It is determined by the absolute numerical value of the correlation coefficient, meaning you ignore the + or - sign.

• Strong relationship: The closer the coefficient is to +1.00 or -1.00, the stronger the relationship.

• Weak relationship: The closer the coefficient is to 0.00, the weaker the relationship.

• Important: The + or - does not determine magnitude. It determines directionality.

• Real-world reality: Perfect correlations of +1.00 or -1.00 are very rare in psychology.

A researcher finds a correlation of r = +0.85 between hours of studying and exam scores. What does the 0.85 tell the researcher?

The relationship is strong because 0.85 is close to 1.

Experimental Methods

Experimenter exposes participants in a study to an experience (treatment) to see if the experience (treatment) they were given affects their behavior. (Occurs in a lab like setting most often under controlled conditions). 

Independent variable

Variables that influence, are associated with, or cause the variation in an outcome or dependent variables.

i.e: variable that the researcher deliberately changes or maninpulates

Dependent variable

The behavior or reaction being measured to see whether the independent variable affected it.

i.e: depends on what happened to the IV.

A researcher wants to determine whether playing violent video games increases aggression in pre-teens. The children are randomly assigned to either play a violent video game or a nonviolent game. Afterward, the researcher measures their aggressive behavior. What is the dependent variable?

The children's aggressive behavior

Experimental group

The group that receives the treatment or condition being tested

Control group

The group that doesn't receive any treatment or condition being tested

Researchers want to determine whether consuming a high-sugar drink increases children's hyperactivity. One group receives the sugary drink, while another group does not. Which group is the control group?

The group that does not receive the sugary drink

Random Sample

Who gets selected for the study?

A researcher wants to study the study habits of college students. They randomly select 200 students from the entire university and then randomly place those students into either a study group or a no-study group. What does the random selection of the 200 students represent?

Random sample

Random assignment

Randomly placing selected participants into groups.

After selecting 200 college students for a study, a researcher uses a random number generator to place each student into either the experimental group or the control group. What does this procedure demonstrate?

Random assignment

Case Study Methods

Use of detailed notes, reports, and written records of behaviors you are studying taken from observations of those behaviors.

(Qualitative data: no statistics or numbers used, more like counselor notes documenting behavior.

A counselor keeps detailed written notes about a client’s behaviors, experiences, and changes over several months. The notes describe what the counselor observes without using numerical statistics. What type of research method is this?

Case study method