Unit II Research Methods

Research Methods 
-Psychology is first and foremost a science, thus is based on research

• Hindsight Bias: the tendency to believe, after learning the outcome, that you knew it all along
• Overconfidence: we tend to think we know more than we do
• The Barnum Effect: it is the tendency for people to accept very general or vague characterization of themselves and take them to be accurate
• Applied Research vs. Basic Research

-Applied research: had clear, practical applications
-Basic Research: explores questions that you may be curious about, but not intended to be immediately used

• Hypothesis

-Expresses a relationship between two variables
-A variable is anything that can vary among participants in a study

• Independent Variable

-Whatever is being manipulated in the experiment 

• Dependent Variable

-Whatever is being measured in the experiment

• Operational Definitions

-Explain what you mean in your hypothesis
-How will the variables be measured in "real life" terms

• Types of Research

1. Descriptive
2. Correlation
3. Experimental

• Descriptive Research

-We cannot say exactly, but we can describe what we see
-Any research that observes and records 
-Types of Descriptive Research:

•  The Case Study (Case Studies): a detailed picture of one or a few subjects

• The Survey (Survey Methods): most common type of study in psychology

-Measure correlation
-Cheap and fast
-Use interview, mail, phone, internet 
-Low response rate
-Random sampling:

1. Identify the population you want to study
2. The sample must be representative of the population you want to study
3. One reason is the False Consensus Effect, the tendency to over estimate the extent to which others share our beliefs and behaviors
4. Low response rate
5. People lie or misinterpret themselves 
6. Wording effect

• Naturalistic Observation

-Watch subjects in their natural environment

-Do not manipulate the environment

-Hawthorne Effect: but even the control group may experience changes

-Just the fact that you know you are in an experiment can cause change

Here's a video you might find entertaining about naturalistic observation!

• Correlation Method

-Correlation expresses a relationship between two variables

-Does not show causation

-Measured used a correlation coefficient

-A number that measures the strength of a relationship 

-Range is from (-1) to (+1)

-The relationship gets weaker the closer you get to zero

-Positive Correlation: the variables go in the same direction

-Negative Correlation: the variables go in opposite directions

• Experimental Research

-Explores cause and effect relationships
-Experimentation: is all about manipulating and controlling variables

-Experimental and Control Groups

1. Experimental: exposes participants to the treatment
2. Control groups: comparison for evaluating the effect

-Experimental Methods:

1. Blind Study: subjects are unaware if assigned to experimental or control group
2. Double-Blind Study: neither subjects nor experimenters know which group is control or experimental

-Descriptive Statistics vs. Inferential Statistics

1. Descriptive Statistics: describe the results of research
2. Inferential Statistics: are used to make an inference or draw a conclusion beyond the raw data

• Measures of Central Tendency

-Central Tendency: where does the center of the data tend to be
-Mode: the most frequently occurring score in a distribution
-Mean: average of scores
-Median: middle score in a rank-ordered distribution
-Range: difference between the highest and lowest scores in distribution
-Standard Deviation: a computed measure of how much scores vary around the mean