Psychological Research Methods

Psychology: Chapter 2, Section 2

Doing Research in the Social Sciences• Like any science, psychology is based on research• “Common sense” assumptions may seem to make

sense, but often they do not have evidence to back them up and many times they contradict each other

• For example, “opposites attract” and “look before you leap” seem like pretty sound aphorisms

• But “birds of a feather flock together” and “he who hesitates is lost” seem to directly contradict those two, and are considered equally sound

• The goal is to test “common sense” assumptions and replace false ideas with facts and evidence

So which is it?

How do youExperiment on People?

•Since they can’t ethically manipulate people’s lives for the sake of an experiment, psychologists must use their observation of the world as their laboratory•Psychologists rely on either quantitative (numerical) or qualitative (survey) data

The Survey Method• Sometimes the best way to find out something about

someone is to just ask them• In a survey, people are asked to respond to a series of

questions about a particular subject• The survey is the most widely used research method among

psychologists• It is ideal for studying large numbers of people• Surveys may be done by having people filling out

questionnaires on their own or being interviewed by a researcher

• The results of surveys not be completely accurate, as respondents may not feel comfortable telling the truth. Respondents may be embarrassed about their answers to personal questions

A survey needs to ask the right questions from enough people, with results often displayed in a bar graph or circle graph

Target Population

• To be an effective measurement, surveys must be sent out to the right number and type of people, using the terms populations and samples

• A target population is all those people with the characteristics a researcher wants to study

• An example of a target population could be all rural Latino males between the ages of 18-35

Sample Population

• It is virtually impossible to interview or question every member of a target population, so instead, researchers study a sample, which is only a part of the target population

• It is not reasonable to ask every rural Latino male the questions, so the sample is a certain number of people chosen to represent the entire population

• The sample should accurately reflect the target population in terms of demographics (age, gender, racial/ ethnic background)

• Samples may be random or stratified

Can a small random group represent the feelings of the larger population?

Representative Samples• The sample must be a representative sample,

which means the people surveyed must accurately represent the target population

• The standard way of getting a representative sample is by random selection

• The researcher must also be aware of effects that may skew the data away from a representative sample

• For example, calling people at home during the day will skew the data toward people who do not have jobs during the day

Random Samples• One of the ways researchers obtain a sample that

they hope is representative is by using a random sample

• In a random sample, individuals are selected by chance from the target population. Each member of the population has an equal chance of being chosen

• If the random sample is big enough, chances are that it will accurately represent the whole population

• A random sample of 1500 people is enough to represent the United States population of 300 million, but a sample of 5 million motorcycle owners would not be a good representative sample

Stratified Sample• In a stratified sample, subgroups of the

population are represented proportionally in the sample

• So if researching what Americans believe in general, 51% of the sample would be female, 12% of the sample would be African Americans, and 3% of the sample would be millionaires

There is a margin of error with any survey result

Technically, the “Total” is a statistical tie, as it is within the margin of error of +/- 3%

How is Survey Information Gathered?• In surveys, information is gathered through either a

questionnaire or an interview, and questions may be closed-ended or open-ended

• A questionnaire is a written set of questions that survey participants answer by themselves

• In an interview, a researcher verbally asks the questions and then records the answers

• Closed-ended questions are like multiple choice questions; they are easy to tabulate, but hard to find underlying attitudes and opinions

• In open-ended questions, the respondent may write an essay or talk at length about an opinion. A lot more detail can be recorded, but it can be hard to score and compare answers

What are the advantages and disadvantages of open ended vs. closed ended questions on a survey?

What can happen if you just rely on volunteers to fill out your long surveys or to stay on the phone with you for 40 minutes to answer all

your questions?

Volunteer Bias• There are many factors that can skew a survey• One of these is volunteer bias, which says that

people who volunteer or complete a survey are different from those who don’t

• People who complete surveys may be nicer, more willing to please, more patient, or more politically involved and willing to talk than others who are not willing to answer any questions

• The results are thus unnaturally biased toward the attitudes of people who are willing to complete a survey

Assessment

• Complete #1-3 on page 34