CHAPTER 2

Methods of Psychology

Crash Course

What are the steps in the

scientific method?

Scientific Method

1. DEFINE the variables we’ll measure

2. Formulate the HYPOTHESIS3. Determine the POPULATION

& SAMPLE to be tested 4. Determine the RESEARCH

METHOD to use5. Summarize the DATA6. Determine appropriate

STATISTICAL MEASURE to analyze data

7. Synthesize RESULTS

Defining the Variables

Variables are specifically defined according to the needs of the researcher

– Specific description of the variables to be measured– Helps researchers determine whether their research

goals were achievedExample – Do women prefer men with a more

masculine or feminine look? Variables

• Masculine Face • Chiseled Jaw • Scruffy • Thick

Eyebrows

• Feminine Face • Prominent cheek bones and

dimples• Man-scaped eyebrows• Long curly eye lashes

What is a hypothesis?

Hypothesis

Hypothesis – a statement of the results that the experimenter expects

Problems That May Skew Data

• Researcher Bias – researcher loses objectivity due to personal involvement and skews the results because of their own desired outcome

• Confirmation Bias – researcher tends to confirm rather than refute actual results in order to confirm existing beliefs

• Hindsight Bias – the tendency to believe, after learning an outcome that one would have foreseen it

Population

All research focuses on a specific population Subjects/Population – people involved in

study Sample – Smaller group representing a

larger group Representative group – truly reflects

larger group

Random Sampling

Selection where each member of a specified population has an equal chance of being selected

Systematic Sampling

Selection of every X element of a group

Ex. Every 3rd person

Experiment

The ultimate reason for completing an experiment is to show cause and effect through manipulation of variables

Variables

Independent – manipulated Dependent – changes due to the

independentConfounding variables – a factor other than

the independent variable that causes a change in the dependent variable

Scientific Method

Control Group – does not participate

Experimental Group – participate

Why is it important to have a control

group and an experimental

group?

What do you think are different

ways to research a hypothesis?

Research Methods

Laboratory Study – conducted in a lab

Field Studies – conducted outside the lab

How can a research psychologist tell if medicine is really

beneficial to a patient or if it is just the power of

suggestion?

Research Methods

PlacebosDouble Blind Study

Field StudySurvey – asking questions

Open-ended question – What type of ice cream do you like?

Closed-ended question – What type of ice cream do you like? Vanilla Chocolate Strawberry

Field StudyNaturalistic Observation – I can’t see you!!!

Never Been Kissed

Never Been Kissed

http://www.youtube.com/watch?v=ECWnJW88fcU

What benefits could their be from completing a naturalistic observation? What would be

some disadvantages?

Field Study

Interviews – Helps obtain personal information

Field Study

Case Study MethodObtain long term information

Usually used to help treat a person

Cannot be used to generalize

Field StudyPsychological Tests – What’s my IQ?

What would be a disadvantage of a psychological test?

Field StudyLongitudinal – Follows specific people their whole lives

Cross sectional – takes examples from all age groups

Are you smarter than your parents?

BLSA

A researcher is interested in how the activity levels of 4-

yr olds is affected by viewing an exciting 30min video of

Teenage Mutant Ninja Turtles versus a 30min calming

video of Barney

IV:

DV:

EG:

CG:

Example

The therapist wants to test a new drug designed to increase the ability of

teenagers with ADHD to take accurate notes in

class

IV:

DV:

EG:

CG:

Example

A researcher is interested in how the activity levels of 4-

yr olds is affected by viewing an exciting 30min video of Teenage Mutant

Ninja Turtles versus a 30min calming video of Barney

IV: viewing 30min video of TMNT

DV: activity level of 4yr olds

EG: 4yr olds watching TMNT

CG: 4yr olds watching Barney

The therapist wants to test a new drug designed to increase the ability of

teenagers with ADHD to take accurate notes in class

IV: teens taking a drug

DV: ability to take accurate notes

EG: teens taking the drugCG: teens not taking the

drug

Correlation

Correlation – a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other

Positive Correlation

Both things increase or decrease in the same direction

Negative Correlation

Relationships increase or decrease in opposite directions

Correlation

Determine whether the following has positive or negative correlation: Blood pressure increases,

cholesterol increases The more you watch TV, the less

you read Students hours at work increase,

students test grades decrease Temperatures decrease, ice cream

sales decrease

Summarize the Data

Graphs, charts, and tables are ways to summarize your data

Determine the Appropriate Statistical Measure

Statistical measures help us to process the data we have collected, and summarize it into quick and clear results

MEASURES OF CENTRAL TENDENCY– MEDIAN

– The true middle value when the original data values are arranged in order

– MODE– The score that occurs most frequently; denoted by M; can be

used with nominal data– Bimodal; multimodal; no mode– a factor other than the IV that does influence the DV

– Mean – The number obtained by adding the values and dividing by

the number of values

Distribution of Data

Normal Distribution - Data is symmetrical mean, median, and mode

Distribution of Data

Skewed Distribution – data lays more in the direction of outlying scores

Synthesis Results

Results and conclusion sections are used to summarize, in words, the information found in the data and statistics sections

Questions You Can Attempt To Answer in Your Conclusion1. Was my hypothesis correct? Why or why not?2. What are some real-life applications to my controlled

experiment?3. What do my graphs and data tables say?4. What are some other studies that have been done on, or

related to, my subject?5. How generalizable are my results?6. Was there any experimenter bias?7. Was this study ethical?8. Could this study have been improved in any way?

What are ethics and why are

they important?

APA Ethics1.The right to decline

participation 2.Openness and honesty3.Confidentiality 4.Assess risks

What about all the cute little animals in the world that are

tested on?