Scientific Practice of Psychology Notes

Descriptive Research - Describe Reality

• Survey

  • NOT method, it’s technique

  • able to generalize for population

  • people lie

  • wording issues

  • cheap

  • social desirability effects

  • easy

• Naturalistic Observation (can see)

  • not good because cannot replicate, unnatural, can’t generalize

  • observer bias

    • when observer knows what to expect and is influenced

  • observer effect

    • know they are being watched

• Case Study - take advantage of unreplicable situation

Scientific Method - observing/experimenting to justify hypothesis

Hypothesis:

• specify variables (anything that can be changed)

• developed from theory

• look for evidence that proves and refutes hypothesis

• support existing theories

• falsifiable if can be proven wrong

• Confirmation Bias

  • search for what you want to be right

Operational Definition: statement of procedure / way in which a researcher is going to measure behaviors or qualities

7 Modern Perspectives of Psychology

1. Biological

   • The body and brain enables human emotions/behaviors

2. Cognitive

   • Human Nature

     • People are information-processing systems

   • Determines Behavior/Mental Process:

     • Mental interpretation of our experience

3. Psychodynamic

   • Human Nature:

     • Driven by dark forces of the unconscious

   • Determines Behavior/Mental Process:

     • Unconscious needs, conflicts, repressed memories, childhood experiences

4. Humanistic

   • Human Nature:

     • Emphasizes human growth/potential

   • Determines Behavior/Mental Process:

     • Influence of self-concept, perceptions, interpersonal relationships, need for personal growth

5. Behavioral

   • Human Nature:

     • Behavior is primarily shaped through learning

   • Determines Behavior/Mental Process:

     • Stimulus cues and our history of rewards and punishments

6. Sociocultural

   • Human Nature:

     • People are social animals, human behavior must be interpreted in social context

   • Determines Behavior/Mental Process:

     • Cultures, social norms, expectations, social learning

7. Evolutionary

   • Human Nature:

     • Behavior is developed and adapted over time

   • Determines Behavior/Mental Process:

     • Natural Selection

Experimental Method

• only research method for investigating cause and effect relationships

Cause and Effect: manipulation of variable to cause effect

Hypothesis:

• if = independence variables

  • experimenter will change

  • cause

• then = dependent variable

  • variable measured

  • effect

  • depends on IV

Population and Samples

Population: all individuals who can participate

• cant use everyone, so use a small group (sample)

Representative Sample: sample that has characteristics similar to those in population, easy to generalize

Random Sample: used to avoid sampling bias

• every member has same chance

Stratified Sampling: ensuring representative, make sure each segment of population is equally represented, easy to generalize

Convenience Sampling: selects participants based on accessibility, can’t generalize (sampling bias)

Experimental Group: has no independent variable manipulated

Control Group: comparison group, measures the dependent variable by not giving experimental treatment

Random Assignment (NOT random sample): ensures all members of sample have equal chance of being in either group

Problems with Experiments

Hindsight Bias: tendency to believe, once an outcome is already known of course, that you would have foreseen it

Overconfidence: very sure of a fact although reality is different

Confounding Variables: only found in experimental research

• differences (other than independent variable) that arise due to poor planning, sloppy work or bias

• variables that a researcher fails to control

Single-Blind Study: participants do not know which group they belong to (control or experimental)

Double-Blind Study: neither participant nor researcher knowns which group the participants belong to

• eliminates experimenter bias (expectations that may influence outcome)

Placebo Effect: real responses to an action or substance based solely on expectations, not actual properties of the action or substance

Correlational Research

• research method

Purpose of correlational research:

1. shows relationship between two variables

2. doesn’t involve manipulation of variables as in an experiment

Weakness:

• correlation is not causation

  • cannot demonstrate cause and effect

Strength:

• predict outcome if know how they are related

Correlation Coefficient: indicates the strength of the relationship between two variables (r value)

Types of Relationships:

• positive (r value = 0-1)

• negative (r value = -1 to 0)

• illusory (r value = 0)

Directionality Problem: occurs when two variables are correlated but it not clear which causes the other

Meta-Analysis: synthesizes results of several previous independent studies on topic

• could summarize multiple correlational studies or experimental studies

Statistics

Outliers: data points that fall beyond the mean

Skewed: data point pile up at one end of the distribution or the other

Bimodal Distribution: types of probability distribution that has two distinct peaks or modes in a data set