Research & Statistics

Different ways to study the mind

8 – 10 %

Understanding Research

Annenberg learner.org Video on demand – discovering psychology:

Updated Edition Understanding Research, 27 minutes Video on Demand

Critical Thinking

Thinking that does not blindly accept arguments and conclusions

• examines assumptions

• discerns hidden values

• evaluates evidence

vs.talk-radio counselors, intuition, common

sense, gut feelings, and psychics

not free from error

the “I-knew-it-all-along” phenomenon

Hindsight Bias

Overconfidence“we think we know more than we actually know”

GRABEETYRNWREAT

How long do you think it would take to

unscramble these anagrams?

GRABEETYRNWREAT

How long do you think it would take to

unscramble these anagrams?

People said it would take about 10 seconds,

on average they took about 3 minutes.

WATER ENTRY BARGE

the need for the Scientific Approach

to Behavior

The Scientific Attitude

The scientific attitude is composed of curiosity (passion for exploration), skepticism (doubting and questioning) and humility (ability to accept responsibility when wrong).

Critical thinking does not accept arguments and conclusions blindly.

Using science, we can differentiate between uniformed opinions and examined conclusions

Examined conclusions lead to our understanding of how people feel, think, and act as they do!

11

A Theory is an explanation that integrates principles and organizes and

predicts behavior or events.

An example: low self-esteem contributes to depression.

Psychologists develop theories to explain behavior;

they apply theories to solve behavior problems

Theory

• system of interrelated ideas used to explain a set of observations

Goals of a scientific investigation

• Measurement techniques that enable clear description of behavior

• Understanding and prediction (hypothesis)• Application and control

• the phenomenon a researcher is attempting to understand will determine the research method used in the investigation

(e.g. experiments are useful for determining cause and effect; the use of experimental controls reduces alternative explanations)

Experimentationthe backbone of psychology research.

It is the ONLY research method capable of showing cause and effect

What are the key steps in scientific investigation

1. Develop a Hypothesis2. Design – which research method?3. Gather objective data4. Analysis and conclusions (refine hypothesis

and retest)5. Report, publish, criticize, replicate the results

17

A Hypothesis is a testable prediction, often prompted by a theory, to enable

us to accept, reject or revise the theory.

i.e. People with low self-esteem are apt to feel more depressed.

Step 1: Hypothesis

18

Research would require us to administer tests of self-esteem and

depression. Individuals who score low on a self-esteem test and high on a depression test would confirm our

hypothesis.

Research Observations

Formulating a testable hypothesis

• Provide operational definitions of the relevant variables

• Operational definitions describe the actions or operations that will be used to measure or control a variable

• Precisely what is meant by each variable in the study

People said it would take about 10 seconds to unscramble the 3

anagrams, yet on average they took about

3 minutes (Goranson,

1978)

Hypothesis: people think they know more than they really do

What would be the best method to test this?

An Independent Variable is a factor manipulated by the experimenter. The effect of the independent variable is the

focus of the study.

For example, when examining the effects of smoking upon intelligence, smoking is the

independent variable.

Independent Variable

22

A Dependent Variable is a factor that may change in response to an independent variable. In psychology, it is usually a

behavior or a mental process.

For example, in our study of the effect of smoking upon intelligence, intelligence is

the dependent variable.

Dependent Variable

the experiment controls other relevant factors by random assignment of participants and double-blind procedure

This increases confidence in the research findings

24

Assigning participants to experimental (smoking) and control (non-smoking)

conditions by random assignment minimizes pre-existing differences

between the two groups.

Random Assignment

25

In evaluating drug therapies, patients and experimenter’s assistants should

remain unaware of which patients had the real treatment and which patients had the

placebo treatment.

Double-blind Procedure

26

summary of Experimentation

smoking

Non-smoking

2. Design the study

• Participants or subjects – persons or animals whose behavior is systematically observed in a study

Select a research method

Experimental Methods– Experimentation

Descriptive Methods– Case study– Survey– Naturalistic observation

Experimental Research

• Experiment – research method in which the investigator manipulates a variable under carefully controlled conditions and observes whether any changes occur in a second variable as a result

• The only method that can determine cause and effect relationships

Hypothesis

a tentative statement about the relationship between 2 or more variables

measurable conditions, events, characteristics, behaviors that are controlled or observed

Variables

Variables

Independent Variable (IV)Dependent Variable (DV)

Researchers need two variables because they want to be able to examine if one thing (a drug, therapy, teaching technique…) has an effect on another (person, people, animals...).

They need to have something to examine and manipulate , the variable of interest (IV)

And they need to have some way to measure the effect, the dependent variable (DV)

Does a change in one variable cause a change in another?

• IV: Independent variable – something the experimenter changes or manipulates to see if it has an impact (it is free to be varied)

• DV: Dependent variable – the variable that will be affected by the change (it depends on the manipulation)

The independent variable is the experimental variable It is the variable that is manipulated by the

research and has an effect on the DV. If there is a change or effect, we may

conclude that the IV affected the DV. The will establish that the IV caused the

change in the DV (this is the magical "cause & effect")

if you want to study the effect of drinking 12 ounces of beer on exam performance, the beer would be the IV and the performance on the exam would be the DV. The performance on the exam is dependent

on the beer we might have one treatment group whose

participants drink the beer and one control group whose participants do not drink the beer

Groups

• Experimental group – they will receive some special treatment (drink beer)

• Control groups – they will not receive special treatment (won’t drink beer)

The two groups must be alike in every way EXCEPT for the variation created by the manipulation of the independent variable

• Independent and Dependent Variables Worksheet Part I

Practice Time

Variables

• Extraneous variables – other things that can affect the outcome of the experiment– any variables other than the independent variable

that are likely to influence the dependent variable in a specific study

• Confounding variables – confounding occurs when two variables are linked together in a way that makes it difficult to sort out their specific effects

Controls and Safeguards

• Ensure that all groups in the experiment are treated equally except for the manipulation of the independent variable.

• To control for extraneous variables

• Random assignment – an equal chance to be assigned to either group or condition in the study

Variations in designing experiments

1. One group of subjects serves as their own control group exposed to both– Experimental condition– A control condition

Variations in designing experiments

2. Manipulation of more than one independent variable in a single experiment, adding the possibility of an interaction

Variations in designing experiments

3. More than one dependent variable is used in a single study, adding a more complete picture of how a manipulation affects a given behavior

Step 3: Collect the data

• Procedures for making empirical observations and measurements

People said it would take about 10 seconds to unscramble the 3 anagrams, yet on average they took about 3 minutes

(Goranson, 1978)

Design: ask people how long it would take to unscramble the anagrams, record their answer, give them the anagrams, record the time is takes them, compare the two

4. Analysis and conclusions

• Data is converted into numbers• Numbers are analyzed using statistics

5. Report the findings

• Journal – periodical that publishes technical and scholarly material, usually in a narrowly defined area of inquiry

• Peer review

The advantages to the scientific approach

• Clarity and precision• Intolerance for error

Strengths and Weaknesses of the Experimental Method

Advantages• Permits conclusions

about cause and effect

• Precise control

Disadvantages• Often artificial,

contrived situations• Limited by ethical

concerns• Some manipulation

of variables would be impossible

Advantages of Experimental Method

*cause-and-effect

*operationalization of variables

*stresses the control of variables

*can implement double-blind or blind procedures

*high internal validity

*may be replicated

Disadvantages of Experimental Method

*reduce external validity

*difficult to establish adequate control conditions

*statistical probability of bias