PSYC 100 Module 2

What is a Science?

• Two core tenets of science:

1. The universe operates according to certain natural laws

2. Such laws are discoverable and testable

What is Psychological Science?

• Human mental processes and behaviour operate according to certain natural laws

• Such laws are discoverable and testable

• But with humans it tends to be pretty messy

How is Psychological Science Different From Other Sciences?

• Humans are incredibly variable

• Few things remain constant across all humans

• Much of psychology’s targets of study involve a tremendous amount of subjective judgement

Psychology

• Using the scientific method to study human behaviour and mental processes

Pseudopsychology (pseudoscience)

• No use of the scientific method when commenting on human behaviour and mental processes

Bias

• Distorted beliefs based on a person’s subjective sense of reality

Deductive reasoning

• Reasoning proceeding from broad basic principles applied to specific situations

• E.g. The home team usually wins → The home team in this particular game will win

Inductive reasoning

• Reasoning process proceeding from small specific situations to more general truths

• E.g. I have collected detailed data about home and away game wins over several seasons → I can say that there appears to be a home arena effect

Hypothetico-deductive reasoning

• Process of modern science where scientists begin with an educated guess, perhaps based on previous research, about how the world works, and then set about designing small controlled observations to support or invalidate that hypothesis

Hypothesis

• A general statement about the way variables relate that is objectively falsifiable

• Usually stated in the form of a prediction or if/then statement

How to Read a Paper

• First Pass

  • Title, abstract, introduction

  • Headings

  • Conclusions

  • References

• Second Pass

  • More detailed read-through

  • Focus on figures, illustrations, other info about findings

  • Keep track of references that would be worth following up on

• Third Pass

  • Much more detailed and effortful read-through

  • Identify underlying assumptions and gaps in the study’s background and methodology

Variable

• Condition, event of situation that is studied

• Types:

  • Independent

  • Dependent

Independent variable (IV)

• The variable that you manipulate

Dependent variable (DV)

• The variable that you measure (or the variable that is changed by the IV)

Operational definition

• How we (the researcher) decide to measure our variables

• There are often hundreds of ways to measure a variable

• When you do research, you have to decide precisely how you are going to measure the IV and DV

Population

• The entire group that is of interest to researchers

Sample

• A portion of the population that is selected for the study

  • Must represent the population

Random selection

• Everyone in the population of interest has an equal chance of being selected

Sampling bias

• Selecting a group that is especially likely to confirm your hypothesis

Descriptive and Correlational Research

• Studies that allow researchers to demonstrate a relationship between variables, without specifying a casual relationship

Experimental Research

• Controlled observations in which researchers manipulate the presence or amount of the independent variable to see what effect is has on the dependent variable

• Allows for casual claims about the relationships between variables

Descriptive Research - The Case Study

• An intensive study of one person

• Advantages:

  • Helps develop early ideas about phenomena

• Disadvantages:

  • Researcher bias

  • You cannot generalize your results to all people

Descriptive Research - Naturalistic Observation

• Observe people behaving as they normally do

• Advantages:

  • More reflective of actual human behaviour

• Disadvantages:

  • Research bias

  • Hawthrone effect - when people change their behaviour because they know they’re being studied

Descriptive Research - Surveys

• Use of a questionnaire or interview

• Advantages:

  • Gather information that can be obtained from other methods

  • May be able to measure relationship strength between variables

• Disadvantages:

  • Participant bias

  • Direction of relationship between variables is unknown

Experimental Research

• Examines how one variable (IV) CAUSES another variable to change (DV)

• Advantages:

  • Can establish cause and effect

  • Can eliminate outside influences

• Disadvantages:

  • Might not be generalizable

  • Sometimes unethical

Experimental group

• The group that is exposed to the IV (manipulation or treatment)

Control group

• The group that isn’t exposed to the IV; this group is used to compare how the IV changes the DV

Random assignment

• The researcher should randomly assign who hoes in which group

• Helps groups be balanced in terms of any other factor that could influence the results

• Different from random selection of participants

Double blind procedure

• Neither the participant nor the researcher knows who is in which group

Statistics

• Describe and measure relationships between variables

  • E.g. mean and standard deviation, correlation coefficient, etc.

Descriptive research

• Goal is to describe the way things are and identify relationships between variables

  • Mean, standard deviation, percentages, etc.

  • Correlations indicate if there is a relationship between the variables

Correlation coefficient

• the strength and nature of the relationship (-1.00 to +1.00)

Positive correlation

• When one variable increases, the other increases

Negative correlation

• When one variable increases, the other decreases

Correlation is Not Causation

• The existence of a relationship between two variables does not mean that one causes the other

Spurious Correlations

• Accidental, meaningless correlations

Experimental research

• Inferential statistics indicate if the hypothesis has been supported or if there is a meaningful difference between the groups

  • Mean, standard deviation, percentages, etc

  • T-tests, F-tests, and other tests are how we tell if one mean is truly different from another mean

Mean

• Average of all of the scores

Standard deviation

• How much the participants’ scores vary from one another

Inferential statistics

• Help to draw conclusions about the data

• Calculate a p-value from your data (the probability of getting the results you did)

  • If the p-value is lower than .05, it means that your results would be pretty unlikely if there is actually no difference/ relationship, which gives us confidence that your data show something real

Replication

• Repeated testing of a hypothesis to ensure results from one experiment are not due to chance

  • It’s always possible that your findings were a fluke or would only have occurred in a specific sample or context. Replication helps us know how “real” a finding is

Code of Ethics

• Canadian Psychological Association

• Research Ethics Boards (REBs) are considered the ethics police. They are a research oversight group that evaluates research to protect the rights of participants in the study

Obtained informed consent

• Obtaining permission from the participant only after they know what the study involves and the risks and benefits of participating

Protect participants from harm and discomfort

• In general, avoid causing harm and discomfort. If harm and discomfort are necessary, it should be the minimum amount necessary and be balanced by strong potential benefits

Protect confidentiality

• In the course of doing research, researchers will often collect sensitive data about people. This information must be protected

Participation must be voluntary

• Research participants must be there of their own free will. We have to take measures to avoid coercion or the appearance of coercion

Deception or incomplete disclosure

• In general, don’t withhold information about the study from participants or mislead participants about the nature of the study

Provide complete debriefing

• Some research questions require some deception or incomplete disclosure. In these cases, participants must be fully informed after the study is over of the deception and the reasons for it