hypotheses

• What is a hypothesis?

  A precise, testable statement of what the researcher predicts will be the outcome of the study
• Why must a researcher produce two hypotheses when conducting research?

  To provide both an experimental and a null hypothesis
• What is an experimental (alternative) hypothesis?

  A hypothesis that predicts something will occur
• What does the null hypothesis state?

  That something significant will not occur
• What must researchers choose between when writing their experimental hypothesis?

  A directional hypothesis and a non-directional hypothesis
• What is a directional (one-tailed) hypothesis?

  A hypothesis that states a specific direction in which the results will go
• What is a non-directional (two-tailed) hypothesis?

  A hypothesis that does not state the specific direction in which the results will go
• What factor helps a psychologist decide which experimental hypothesis to pick?

  If there is previous research that has found a specific finding
• What must a hypothesis include?

  Both the independent variable and the dependent variable
• What is an independent variable (IV)?

  The variable that the researcher is manipulating
• How many levels does an independent variable usually have?

  Two or more levels
• What is a dependent variable (DV)?

  The variable that the researcher is measuring
• How many levels does a dependent variable usually have?

  Usually only one level
• What does the term "operationalising variables" mean?

  Clearly defining a variable by providing an accurate metric
• How would you operationalise the variable "amount of water"?

  By measuring it in ml or litres
• How would you operationalise the variable "happiness"?

  By defining it through a specific metric, such as a happiness scale
• What are the key components of a hypothesis?

  • Must include both independent and dependent variables
  • Both variables must be operationalised
• What are the types of hypotheses researchers can choose from?

  • Experimental (alternative) hypothesis
  • Null hypothesis
  • Directional (one-tailed) hypothesis
  • Non-directional (two-tailed) hypothesis
• What is the importance of operationalising variables in research?

  • Provides clear definitions
  • Makes variables specific and objective
  • Allows for mathematical measurement
• What must you produce when conducting an experiment?

  An alternative hypothesis and a null hypothesis
• What do psychologists do at the end of an experiment?

  They analyze their findings
• What is the purpose of statistical tests in psychology?

  To determine if the results are significant
• What should you do if the findings of an experiment are significant?

  Accept the alternative hypothesis and reject the null hypothesis
• What should you do if the findings of an experiment are not significant?

  Accept the null hypothesis and reject the alternative hypothesis
• What are the two types of errors in hypothesis testing?

  • Type I error: Accepting the alternative hypothesis when it should be rejected (false positive).
  • Type II error: Accepting the null hypothesis when it should be rejected (false negative).
• What is a Type I error?

  A Type I error occurs when a psychologist accepts the alternative hypothesis incorrectly
• What is a Type II error?

  A Type II error occurs when a psychologist accepts the null hypothesis incorrectly
• What does a 5% significance level indicate?

  There is a 5% chance the results happened by accident
• What does a 0.01 (1%) significance level indicate?

  There is only a 1% chance that the results happened by accident
• How can you reduce Type I and Type II errors?

  • Reduce Type I error: Make the test stricter by accepting a higher threshold (e.g., 0.01).
  • Reduce Type II error: Make the test less strict by accepting a lower threshold (e.g., 0.05).
• What is the consequence of not accurately conducting statistical tests?

  Psychologists can make errors in deciding which hypothesis to accept or reject
• What is a null hypothesis?

  A statement that indicates no significant effect or relationship
• What is an alternative hypothesis?

  A statement that indicates a significant effect or relationship