The research hypothesis states that there is no difference between scores on dependent variables. ...

The research hypothesis states that there is no difference between scores on dependent variables.
 
  Indicate whether the statement is true or false

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Reflect on the Are You Equipped Now at the end of the chapter. It may be such that participants wanted so strongly for this new treatment to work that they experienced pain relief.
 
  If this did indeed occur, which of the following was a threat to internal validity?
 
  a. placebo effect
  b. demand characteristics
  c. selection
  d. maturation

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____________: An objectie extension of the question that was originally posed.
 
  Fill in the blanks with correct word

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Jason is interested in the topic of perception. He has participants complete a task on a computer and measures reaction and number of errors.
 
  Jason is thinking of repeating this task after the participants have been exposed to the independent variable. Which of the following reasons bests describes why Jason might not want to have participants complete the task again?
 
  a. ethical concerns
  b. more statistical variance
  c. practice effects
  d. none of the above

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Stratified sampling is also known as cluster sampling.
 
  Indicate whether the statement is true or false