PT 1.2.1

  1. inferences
    logical deductions about events that cant be observed directly
  2. what are descriptive stats?
    methods used to provide a concise descroption of a collection of quantitative information
  3. inferential statistics
    methods used to make inferences from a small group of people (sample), to a large group of people (population)
  4. What type of stats is psych testing based on?
    inferential stats
  5. what is measurement?
    application of rules for assigning numbers to objects
  6. What are 3 things that scales can have?

    -equal intervals

    -absolute 0
  7. (things scales can have) Magnitude
    • moreness
    • *taller or shorter
  8. (things scales can have) Equal intervals
    • the difference between two points next to each other is the same
    • *such as inches
  9. (things scales can have) absolute 0
    • it is possible to have none of a particular quality being measured
    • *heart rate of a person is 0, nothing
  10. 4 types of scales

    - ordinal


    - ratio
  11. (types of scales) nominal
    • -not really scales just assigning random designator number to people or things
    • *either yes or no
  12. (types of scales) Ordinal scales
    has the property of moreness but not equal intervals or absolute 0
  13. (types of scales) interval scales
    • has magnitude and equal intervals but not necessarily the absolute 0
    • *temp in F or C
  14. (types of scales) ratio scales
    has magnitude, equal intervals, and absolute *focus more on this one
  15. For each observation in a nominal data, how mmany categories can it go to?
    • one
    • *it cannot be used for mathematical manipulations but can be used for frequency dist.
  16. Can ordinal data be manipulated and difficult to interpret
    it can be manipulated and difficult to interpret
  17. Can we make statements about ratios with interval data?
  18. frequency distirbution
    summarizes the scores of a group of individuals in terms of how frequently each value is obtained
  19. What does a bell-shaped curve distribution mean?
    mean, median, and mode are at the same spot
  20. positive skew meaning?
    more scores are above the mode than below it
  21. negative skew meaning?
    more scores are below the mode than above it
  22. class interval
    • is the distance between 2 consecutive measurements
    • *one decides the meaningful difference between one measurement and the next one
    • *temp, money, length
  23. percentile is a measure of what?
    • relative performance
    • *population hsould be specified
  24. standard deviation
    an approximation of the average deviation around the mean
  25. variance
    variation of the scores around the mean calculated as squared deviation around the mean
  26. which is more meaningful, SD or vairnace?
  27. what does lower case sigma refer to?
    standard deviation of population
  28. what does the S stand for?
    standard deviation of a sample drawn from that population
  29. what does the z-score indicate?
    distance of a score from the mean in SD
  30. Whats a zscore of 1.0 mean in percentiles?
    the persons score is at ~84th percentile
  31. whats a zscore of -1.0 mean in percentile?
    ~16th percentile
  32. What is the SD of wechsler IQ tests?
    15 bc that was the closest to the standford-binet which was 16
  33. why are the wechsler IQ scores significant?
    • they are based on population stats alone and no longer make use of calc. of mental age.
    • *score tells us where the individual scores relative to their peers
  34. what is another name for standard normal distribution?
    symmetrical binomial probability distribution
  35. who developed a system in which the SD comes in equaling to 10?
    W.A McCall
  36. For McCalls T, what number is the mean?
    50 rather than 0
  37. whats formula of converting z score into t-score?
  38. how do quartile systems divide percentage scale?
    into 4ths
  39. how do deile systems divide percentage?
  40. What are stanines?
    divided scores into 9ths making 3 groups of lower, middle, and upper.
  41. what do norms refer to?
    • the performances by defined groups on particular tests
    • *these are the scores a sample is compared to
  42. what do norm referenced tests do?
    • compare individuals to a normative group
    • *make somebody look bad helps you look better
  43. what do criterion referenced tests do?
    • compare an individual to a crtierion on specific taks, skills, or knwoledge.
    • *these are used mainly for diagnostic purposes
    • ***making somebody else look bad doesnt help you
  44. If there is a standardization sample, the test has ______ _____
    normative data
Card Set
PT 1.2.1
chapter 2