Basic Terms

  1. reliability
    consistently gives the same answer
  2. validity
    • measures what it is supposed to measure
    • accuracy 
  3. internal validity
    the study really investigates the proposed question
  4. external validity
    how well the study results are generalized across populations, settings and time
  5. population
    entire group or class of subjects, variables, concepts, or phenomena
  6. census
    process of examining every member of a population
  7. sample
    a subset that is taken to be representative of the entire population
  8. probability sample
    • selected according to mathematical guidelines whereby the chance for selection of each unit is known
    • quantitative
  9. non-probability sample
    • selected for convenience of the researcher
    • qualitative research
  10. convenience sample
    • available sample
    • ex. group of students in mass media
  11. volunteer sample
    individuals are not selected mathematically
  12. purposive sample
    subjects selected on basis of specific characteristics
  13. quota sample
    subjects selected tot meet a predetermined or known percentage
  14. quota sample example
    ex. survey composed of 10% VCR owners and 90% non-VCR owners reflects the population characteristics
  15. Network (snowball) sample
    based on other sample member's referrals
  16. random sample
    each subject in pop has an equal chance of selectoin
  17. random sample example
    ex. reading table of numbers
  18. systematic sampling
    every nth subject is selected from a population
  19. systematic sample example
    ex. blocks of 4 people and then every third person within that block
  20. sampling frame
    complete list of members in the pop of sample
  21. periodicity
    the order of the items in the pop list may bias selection
  22. periodicity example
    ex. every 10th tv program from a list may be an ABC program
  23. stratified sampling
    used to guarantee a subsample of the population is represented; homogenous
  24. stratified sample example
    ex. graduate students out of all students
  25. larger
    sample size: the ______, the better
  26. independent variables
    predictor variables
  27. dependent variables
    criterion variables
  28. operational definition
    • specifies procedures to be followed in measuring a concept; clear statement about what is to be observed
    • how the variable is measured
  29. operational definition
    ex. go to the grocery store and see sign for milk; go to sign and what's underneath it is milk
  30. constitutive definition
    defines a construct using other constructs (like a dictionary)
  31. construct
    a term that expresses an abstract idea formed by generalizing from particulars and summarizing related observations.
  32. construct examples
    ex. table” – concept that represents a wide variety of observable objects, ranging from a plank supported by concrete blocks to a piece of furniture commonly found in dining rooms.“emo”“Taffies” – technologically advanced families
  33. continuous variable
    can take on any value, including fractions; can be meaningfully broken into smaller subsections
  34. continuous variable examples
    ex. height (can distinguish between 72.12 inches tall and 72.13 inches tall); time spent watching television (person A spent 3.12 hours watching while person B spent 3.13 hours); the average number of children in a family
  35. discrete variables
    includes only a finite set of values; cannot be divided into subparts
  36. discrete variables examples
    number of children in family (bc the unit is a person); political affiliation; gender of a person; population
  37. nominal
    numerals or other symbols are used to classify people, objects, or characteristics; labels that stand for the respective categories, have no significance
  38. nominal measurement example
    rocks can be classified into 3 categories: igneous, sedimentary, metamorphic. A scientist who assigns a 1 to igneous, a 2 to sedimentary, and a 3 to metamorphic has created a nominal scale
  39. ordinal
    • ranked along some dimension, such as from smallest to largest;
    • numbers generally have some mathematical meaning;
    • equivalence – all in one category are treated equally
  40. ordinal measurement example
    ex.  “socioeconomic status” – categorizing families according to class: lower, lower middle, middle, upper middle, upper
  41. interval
    • has all the properties of an ordinal scale and the intervals between adjacent points on the scale are of equal value;
    • property of equal differences
    • no true zero (can't have it)
  42. interval measurement example
    ex. temperature – the same amount of heat is required to warm and object from 30 to 40 degrees as to warm it from 50 to 60 degrees.
  43. ratio
    • interval properties
    • has true zero
  44. ratio measurement example
    Time spent watching TV or number of words per story
  45. qualitative research
    methods of data collection including focus groups, field observation, in-depth interviews, case studies, etc
  46. quantitative research
    • variables under consideration must be measured
    • large samples often used to generalize results
  47. likert scale
    uses interval measurement for scale in which respondents strongly agree, agree, are neutral, disagree, or strongly disagree with the statements
  48. semantic differential scale
    uses interval measurement for scale consisting of 7 spaces between two bipolar adjectives (good___bad), asked to choose where his or her position lies
Card Set
Basic Terms
Lydia Fielder