Myers PSYCHOLOGY

Seventh Edition in Modules

Module 2 Research Strategies: How

Psychologists Ask and Answer Questions

James A. McCubbin, Ph.D.Clemson University

Worth Publishers

Observation

The simplest scientific technique is observation. It is systematic. This means that you watch for specific behaviors and record what you see.

For example you might be asked to document the color of the cars that go by your house between the hours of 5 pm and 7 pm.

An example would be that you are asked to watch or observe two dogs playing in your backyard and write down what you see. The information that you collect is called data.

Data Collection

There are many ways that data can be collected. Data might be collected with a video recording device, by administering a questionnaire or using a checklist.

The important thing is that it has to be collected so that other scientists who wish to repeat the observations can do so. No experiment is conducted with this method. The researcher does not attempt to change the environment during the data collection phase. The data are analyzed, and researchers look for interesting or important patterns. This technique can be used in studies of children.

Types of Observation

There are three types of observation – naturalistic observation, controlled observation and clinical observation.

Naturalistic Observation

Naturalistic observation is observational research that takes place in a natural or everyday setting such as a school. Usually there is an effort to minimize the observer’s impact by carrying out observations secretly or from a hidden vantage point

Examples

Observing and recording the behaviour of students in the cafeteriaObserving and recording the behaviour of geese in the fieldObserving and recording the behaviour of children at recess in the playground

Controlled Observation

Controlled observation occurs when observational research is carried out under carefully arranged conditions. Each subject is exposed to the same situation to see differences between individual reactions.

Examples

Observing and recording the behaviour of students in the cafeteria when someone is crying or not cryingObserving and recording the behaviour of geese in the field when a horn is blaring and is not blaringObserving and recording the behaviour of children at recess in the playground when there is an adult supervisor present and not present

Clinical Observation

Clinical observation consists of observations made by a skilled clinician interacting with a patient or client. The clinician takes notes on the interaction, usually immediately after the interview or meeting with the client.

Bias

Your observations may be influenced by what you want to discover. This is called researcher bias. Bias occurs whenever any factor unfairly increases the likelihood that the researcher will reach a particular conclusion. Researchers try to avoid bias.

The Need for Psychological Science

Critical Thinking thinking that does

not blindly accept arguments and conclusions examines

assumptions discerns hidden

values evaluates evidence assesses conclusions

The Amazing Randi—Skeptic

Participant Bias

Researchers must also watch out for participant bias. This it the tendency for research participants to respond in a certain way because they know they are being observed or they believe they know what the researcher wants.

Case StudiesResearchers who study individuals in depth

are using the case study method. This method is prone to bias. Sometimes a case study is all that can be done.

For example, the only way to get information on the effects of child abuse is to find people who have reported abuse and study that person or group of people. Since no two cases are ever exactly alike, there is always some doubt as to the real effects.

Description

Case Study observation

technique in which one person is studied in depth in the hope of revealing universal principals

Is language uniquely human?

Correlational Studies

There are many times when it’s useful to know if two things or variables are related. The research technique that is used is the correlational study.

Correlation Correlation Coefficient

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

Correlation coefficient

Indicates directionof relationship

(positive or negative)

Indicates strengthof relationship(0.00 to 1.00)

r = +.37

Correlation

Scatterplot a graphed cluster of dots, each of which

represents the values of two variables the slope of the points suggests the

direction of the relationship the amount of scatter suggests the

strength of the correlation little scatter indicates high correlation

also called a scattergram or scatter diagram

Correlation

Perfect positivecorrelation (+1.00)

No relationship (0.00) Perfect negativecorrelation (-1.00)

Scatterplots, showing patterns of correlations

CorrelationHeight and Temperament of 20 Men

123456789

10

11121314151617181920

80636179746962757760

64767166737063716870

75666090604242608139

48697257637530578439

SubjectHeight in

Inches Temperament SubjectHeight in

Inches Temperament

Correlation

Scatterplot of Height and Temperament

55 60 65 70 75 80 85

959085807570656055504540353025

Temperamentscores

Height in inches

CorrelationThree Possible Cause-Effect Relationships

(1)Low self-esteem

Depression

(2)Depression

Low self-esteem

Low self-esteem

Depression

(3)Distressing events

or biologicalpredisposition

could cause

could cause

could cause

or

or

and

Illusory Correlation

Illusory Correlation the

perception of a relationship where none exists

Conceive Do not conceive

Adopt

Do notadopt

disconfirming evidence

confirming evidence

disconfirming evidence

confirming evidence

Other forms of data collection

One of the easiest forms of data collection is administering a questionnaire. This is very similar to taking a poll. Professionals usually conduct surveys and polls, while amateurs administer questionnaires.

Description

Survey technique for ascertaining the self-

reported attitudes or behaviors of people usually by questioning a representative,

random sample of people False Consensus Effect

tendency to overestimate the extent to which others share our beliefs and behaviors

The Need for Psychological Science

Hindsight Bias we tend to believe, after learning an

outcome, that we would have foreseen it

the “I-knew-it-all-along” phenomenon Overconfidence

we tend to think we know more than we do

Description

Population all the cases in a group, from which

samples may be drawn for a study Random Sample

a sample that fairly represents a population because each member has an equal chance of inclusion

Longitudinal and Cross-sectional studies

Longitudinal studies follow the same group of individuals over many years.

Cross-sectional studies compare people of different ages at one time.

These studies are techniques of particular use to developmental psychologists, who study how individuals change throughout the lifespan.

The Need for Psychological Science

Psychologists, like all scientists, use the scientific method to

construct theories that organize observations and imply testable hypotheses

The Need for Psychological Science

Theory an explanation using an integrated

set of principles that organizes and predicts observations

Hypothesis a testable prediction often implied by a theory

The Need for Psychological Science

The Need for Psychological Science

Operational Definition a statement of procedures

(operations) used to define research variables

Example: intelligence may be operationally defined

as what an intelligence test measures

The Need for Psychological Science

Replication repeating the essence of a

research study to see whether the basic finding extends to other participants and circumstances

usually with different participants in different situations

Description

Experimentation

Experiment an investigator manipulates one or

more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable)

by random assignment of participants the experiment controls other relevant factors

Experimentation

Experimental Condition the condition of an experiment that

exposes participants to the treatment, that is, to one version of the independent variable

Control Condition the condition of an experiment that

contrasts with the experimental treatment serves as a comparison for evaluating the

effect of the treatment

Confounding Variables

The individual differences among participants are the largest category of a special kind of variable known as confounding variables.

These are variables other than the IV that could produce a change in the DV. Confounding variables must be controlled for. You must eliminate as many of these as possible before you get your sample so that your results are accurate.

Control

Experimenters use a variety of techniques to minimize the effects of confounding variables. The researcher must account for the following:

individual differences among participantsenvironmental differences such as lighting,

noise and temperatureDid both groups study at the same time of

day? Were the room temperature and lighting conditions the same for both groups?

Experimentation

Random Assignmentassigning participants to experimental and control conditions by chance

minimizes pre-existing differences between those assigned to the different groups

Experimentation Independent Variable

the experimental factor that is manipulated

the variable whose effect is being studied Dependent Variable

the experimental factor that may change in response to manipulations of the independent variable

in psychology it is usually a behavior or mental process

Expectation Effects

Expectation effects include making sure that participants are not aware of the hypothesis of the experiment. If they were, their expectations could influence the outcome.

Did the experimental group expect to do better? Did the researchers expect the experimental group to do better?

Procedures

To control for such effects, experimenters use three different procedures the single blind procedure, the double blind procedure and the placebo.

Single Blind Procedure

Experimenters often use a blind or masked procedure, which means that they don’t tell participants what the hypothesis is until after the data are collected.

Double blind Procedure

In this procedure the people collecting the data don’t know the expected outcome of the research or which participants are in which group and the participants don’t know if they are in the experimental group or the control group.

Placebo

Experimenters use this special kind of control in all drug studies. It involves a non-active substance or condition that is administered instead of the drug.

Review We are conducting an experiment to test the hypothesis that students assigned to use their MP3 player each day in the library while studying will have lower average grades at the end of the semester than students banned from using their MP3 player. The IV is the presence or absence of the MP3 player. The DV is the average grades at the end of the semester. Students were randomly selected from the entire population of students who use the library to study. We randomly assigned students to either the experimental group (using the MP3 player) or the control group (not using the MP3 player). All environmental conditions are as similar as possible.

Reliability and Validity

There are safeguards required for experiments to make sure that the research is both valid and reliable.

Research is valid when it measures what the researcher set out to measure; it is accurate.

Research is reliable when it can be replicated; it is consistent.

Experimentation

Review of Experimental Method1. Develop the hypothesis.2. Create operational definitions for the independent and dependent variables.3. Randomly select a sample of participants from the population.4. Randomly assign the participants to the experimental and control groups.5. Expose the experimental group, but not the control group, to the IV. If necessary, use a placebo with the control group to balance expectations.6. Control for other confounding variables by using a double-blind procedure and treating both groups the same except for exposure to the IV.7. Learn the impact of the IV by measuring the DV for both groups and use statistical analysis.

Examples Read the following scenarios and determine if the method used is

correlational, experimental or observational. 1. Professor Black is interested in understanding the relationship

between self-esteem and anxiety in group situations. 2. Researchers at the University of Manitoba are interested in studying

relationships among employees at Boeing Aircraft. These researchers decide to go and observe the interactions of coworkers in the factory. 

3. Professor Guptah wishes to study the effects of food deprivation on learning in rats.  

4. Dr. Cheung and her colleagues wish to study the aggressive behaviour of elementary school children by observing the children at play.

5. A group of researchers from a child advocacy group wishes to examine the relationship between exposure to televised violence and later aggressive behaviour in children by asking parents to report on how much television their child watches and what types of programs their child has watched.

 

Examples continued

6. Dr. Beauchamp wishes to investigate the effects of a new training program at McDonald’s on employees’ job performance.

7. A group of researchers wishes to study the organizational culture of successful schools.

8. Dr. Cortez is interested in the relationship between the different strategies that a therapist uses and how effective those strategies are.

9 A group of researchers is interested in the effects of caffeine drinks like Red Bull on test performance.

10. Dr. Courchene is interested in studying peer influence among high school students by recording their clothing choices, hairstyles.

Use of Statistics

Without a basic understanding of statistics you are at a serious disadvantage because statistical information is all around us. For example, you hear that 9 out of 10 dentists want you to use a particular toothpaste, you learn about the earned run averages of the Winnipeg Goldeyes, and you hear that blue is the most favorite color of M and M. The overall purpose of statistics is to make data more meaningful.

Frequency Distributions

A frequency distribution is an ordered list of scores from highest to lowest or lowest to highest. The data can then be easily presented as a bar graph.

Measures of Central Tendency 1. Mode The mode is the score that occurs most frequently in the distribution.

It is not the best source of information because it is possible for the mode to not be even close to the center of the distribution.

2. Mean The mean is the most familiar measure of central tendency. It is

commonly called the average. You calculate it by adding together all of the scores and then dividing by the number of scores that you added together. The mean can be misleading if there are some really high or really low scores.

Median 3. The median shows us the middle of a distribution. Once you

have put all the scores in order you find the middle scores. The extremely high scores and the extremely low scores will not have an impact on the middle score.

 

Measures of Variation

Even though it is important to know where the center of a distribution falls it is also important to know how different or varied the scores are from the mode, mean and median. RangeThe simplest measure of variation is the range. It is the difference between the highest score and the lowest score.

Standard Deviation

Standard deviation is a measure of the overall variation of a distribution of numbers. The smaller the standard deviation, the more closely the scores are to the mean. The higher the standard deviation the more spread out the scores are. Normal DistributionA lot of psychological data can be represented in a graph called a normal distribution, or bell-shaped curve. The right and left sides of the curve are identical. The highest point represents all three measure of central tendency: the mode, the mean, and the median.

Comparative Statistics

The two major comparative statistics are percentage and percentile rank.

Percentage compares a score to an imaginary score of 100.

Percentile rank compares one score with other scores in an imaginary group of 100 individuals. It tells you where a particular score stands in that group and how many people had equal or lower scores.

 

Correlation Coefficient The correlation coefficient is a number that

represents how strong a relationship is between two variables. The number has a value between -1 and +1.

If the correlation coefficient (r) has a value of -1 then we have a perfect negative correlation. This means that every time one variable increases the other variable decreases by the same amount.

If r=+1 then we have a perfect positive correlation. This means that every time one variable increases the other variable increases by the same amount.

If r=0 then there is no correlation.

Scatterplot

Remember r values can be anywhere between -1 and +1. They are represented in a graph called a scatterplot. The data is mapped as dots on this type of graph.

Statistical Inference

The statistics so far in this lesson are called descriptive statistics because they describe data in a way that makes them more meaningful.

Another kind of statistics that is important for psychologists is called inferential statistics. This lets us make decisions or reach conclusions about a set of data.

 

Three factors:

1. The difference between the two groups’ means. If the means are far apart, the result is more likely to be significant.

2. The number of participants. If each group has only a few people, the results are not as likely to be as significant as they would be if each group has a large number of randomly selected people in it.

3. The standard deviation of the two groups. If the scores of each group are mostly packed closely to each mean, then the results are significant.

Frequently Asked Questions about Psychology

Why do psychologists study animals?

Is it ethical to experiment on animals?

Is it ethical to experiment on people?

Human Research Guidelines

Informed consent – Participants must know that they are involved in research and give their consent. It is at this time that participants need to be told about any potential risks. Coercion - Participation must be voluntary. No one can be forced to be in a study. Participants have the right to refuse to participate or to withdraw at any time from the study.Anonymity/Confidentiality – Participants’ privacy must be protected. The researcher must never reveal their identities. Risk – Participants can’t be placed in any significant mental or physical risk. Debriefing – Participants must be told the purpose of the study and provided with ways to contact the researchers about the study results.

Animal Research Guidelines Clear scientific purpose – The research must

answer a specific, important scientific question. Animals are chosen because they are best-suited.

 Humane treatment – The animals must be cared for and housed in a humane way.

Legal possession of animals – The animals used in research must be purchased from legal companies. If wild animals are used they must be trapped in a humane manner.

 Minimum suffering - The experimental procedures must be designed to use the least amount of suffering possible. 

Why Use Animals? Psychologists use animals in research for several

reasons. Some of these reasons are: Many psychologists are simply interested in animal

behaviour. There are biological and behavioural similarities

between animals and humans. By studying animals we can learn things that apply to humans. 

Because the life span of most animals is shorter than humans we can study genetic effects over generations faster than in humans. 

Researchers have more control over experiments with animals than with humans.