Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

9 Cards in this Set

  • Front
  • Back
Internal Validity
reqs proper selection of study groups, lack of error in measurement, and ctrl for confounding factors
External Validity
ability to extrapolate from a sample population to a target population

* how closely does a measurement represent the truth?
reproducibility, repeatability, precision, consistency

* how consistently to repeated measurements agree?
Random Error
fluctuations around a true value of a parameter because of sampling variability

can occur as a result of poor precision, sampling error, or variability in measurement
Systematic Error (Bias)
bias: systematic difference or distortion from the truth in a particular direction

illustrated by values placed away from true value in center

resulting estimate less accurate

much more serious problem for study validity than random error

bias can result in findings that are distorted:
- toward null hypothesis
- away null hypothesis
Selection Bias
study population doesn't represent target population
Information Bias
occurs during data collection

1) misclassificaton: not classifying people properly in terms of exposure and outcome

2) ecological fallacy: people with the outcome may not be the ones with exposure

3) regression to the mean

* includes recall bias
presence of an extraneous variable which is a risk factor for an effect among unexposed people and is associated with exposure under study