Hypothesis Development

Forming a Hypothesis

  • A hypothesis is a statement predicting the results of a study (best educated guess)

    • Can be descriptive or casual

    • Often based on theories and results already known

Using the Literature to Form Hypotheses

  • Descriptive hypotheses are predictions about the results of a study that describe the behavior or the relationship between behaviors

  • Casual hypotheses are predictions about the results of a study that includes the causes of a behavior

  • Must be precise and logical

  • Must be testable

  • Reliability = consistency

    • Using the same procedure to measure the same phenomenon and obtaining the same results

    • A reliable measure is consistent between two or more separate measurements

    • Must be clearly specified!

Validity

  • Internal validity is the degree to which a study provides casual information

    • The design of experiment ensures the IV (independent variable) caused the measured difference in the DV (dependent variable)

    • “Was the research done right?”

  • External validity is the degree to whch results can be generalized beyond the specifics of your sample

    • “Does this happen in other settings? Everyday, labs?”

Data Collection Techniques

  • Naturalistic observation includes unobtrusively observing individuals in their natural/normal environment

    • Important to develop a coding scheme (guideline on how to pull relevant information)

      • Ethograms are lists of defined behaviors

  • Inter-observer/inter-rater reliability

    • Measure of the degree of agreement between 2 independent observers

  • Surveys/Questionnaires

    • Asks individuals to self-report their behaviors and attitudes

    • Questions need to be tested for reliability and validity

    • Likert Response Scale

      • (1 = Strongly Disagree → 5 = strongly agree)

  • Interviews

    • Requires coding scheme

    • More flexible w/questions

  • Systematic Observations

    • Observing behavior under controlled conditions

    • Includes memory accuracy, problem solving ,speed, and Implicit Association Test

  • Archival Data

    • Observing behavior from pre-existing records/data

    • Content analysis

      • Observation technique that invlves analysis of what someone has said or written

Research Designs

  • The specific method a researcher uses to collect, analyze, and interpret data

  • 3 Main Types

    • Descriptive research (case study)

    • Correlational research

    • Experimental research

Descriptive Research

  • Descriptive studies seek to answer…

    • Who, what, where, when, how

  • When are these studies appropriate?

    • Understand prevalence and trends

    • Explor a phenomenon in depth

    • Examining a phenomenon in a different population

  • Case Study

    • A research design that involves intensive study of an individual or group of individuals and their behaviors

    • Often use naturalistic observations, interviews, or archival data to learn about behavior

    • Good example is Henry Molaison

Correlational Research

  • Examines the relationships between multiple dependent variables w/o manipulation of variables

  • Main goals include…

    • Determine if different behaviors are connected and occur or vary together

    • Predict a change in one from observing change in another

  • 2 Types of relationships

    • Positive correlation (0 to +1.00)

      • A direct relationship, two things increase together or decrease together

    • Negative correlation (0 to -1.00)

      • An inverse relationship (they do the opposite) as one thing increases, the other decreases

Problems with Causality

  • Correlational research cannot be used to draw conclusions about the casual relationships among variables

    • Third variable problem: Presence of extraneous factors in a study that affects the dependent variable, decreasing internal validity

  • CORRELATION DOES NOT EQUAL CAUSATION

Experimental research

  • Assesses the impact of an experimental manipulation (independent variable) on an outcome of interest (dependent variable)

  • Control for confounding variables by using random assignmet, so you can assess cause and effect

  • Independent Variable

    • Manipulated by the researcher (can also be held constant or added to)

    • Levels of IV: Different conditions participants experience

  • Dependent Variable

    • The variable being measured/observed

  • Control group

    • Group of participants that do NOT receive the experimental treatment/manipulation

Quasi-Experiment Research

  • A comparison is made but participants are NOT randomly assigned to conditions

    • Not all variables can be manipulated

    • Use naturally occurring groups