FINAL REVIEW Flashcards
BIVARIATE TABLE
a table that displays the joint frequency distributions of 2 variables
CELLS
the cross classification categories of the variables in a big aria the table
X^2 (CRITICAL)
the score on the sampling distribution of ALL possible sample chi squares
X^2 (OBTAINED)
the test statistic as computed from SAMPLE RESULTS
CHI SQUARE TEST
a non-parametric test of hypothesis for variables that have been organized into a bivariate table
COLUMN
the vertical dimension of a bivariate table
- each column represents a score on the INDEPENDENT VARIABLE
EXPECTED FREQUENCY (fe)
the cell frequencies that’d be expected in a bivariate table if the variables were INDEPENDENT
GOODNESS OF FIT TEST
an additional use for chi square that tests the significance of the distribution of a single variable
INDEPENDENCE
the NULL hypothesis in the chi square test
- 2 variables are interdependent if, for all cases, the classification of a case on one variable has NO EFFECT on the probability that the case will be classified in any particular category of the second variable
MARGINALS
the row and column subtotals in the bivariate table
NONPARAMETRIC
a “distribution free” test
- these tests don’t assume a normal sampling distribution
OBSERVED FREQUENCIES (fo)
the cell frequencies actually observed in a bivariate table
ROW
the HORIZONTAL dimension of the bivariate table, conventionally representing a score on the dependent variable
THE DECISION TO REJECT THE NULL HYPOTHESIS IS NOT SPECIFIC
- means that only ONE statement in the model OR the null hypothesis is WRONG
WHAT LEVEL CAN A CHI SQUARE TEST BE CONDUCTED AT
can be measured at the NOMINAL LEVEL, which is the lowest level of measurement
- because it is NONPARAMETRIC, chi square requires NO ASSUMPTION at all about the shape of the population or sampling distribution
THE ____ CERTAIN WE ARE OF THE MODEL, THE _____ OUR CONFIDENCE THAT THE NULL HYPOTHESIS IS THE FAULTY ASSUMPTION
more, greater
A “_____” OR EASILY SATISFIED MODEL MEANS THAT OUT DECISION TO ______ THE NULL HYPOTHESIS CAN BE MADE WITH EVEN GREATER CERTAINTY
weak, reject
CHI SQUARES FLEXIBILITY
can be used and conducted with any variables at ANY LEVEL OF MEASUREMENT
WHAT ARE A BIVARIATE TABLES TWO DIMENSIONS
- the horizontal (across) dimension (ROWS)
- the vertical (up and down) dimension (COLUMNS)
ROW = ________
COLUMN = ___________
dependent, independent
SUBTOTALS THAT ARE ADDED TO EACH COLUMN AND ROW IS CALLED _________
marginals
WHAT IS REPORTED AT THE INTERSECTION OF THE ROW AND COLUMN MARGINALS
the total number of cases
ON A TABLE, WHAT VARIABLE IS LISTED FIRST
the dependent variable
THE CONCEPT OF INDEPENDENCE
the relationship between the VARIABLES, not between SAMPLES
WHAT IS THE NULL HYPOTHESIS FOR CHI SQUARE
that the variables are INDEPENDENT
IF THE NULL HYPOTHESIS IS _____ AND THE VARIABLES ARE _________, THEN THERE SHOULD BE _________ DIFFERENCE BETWEEN THE EXPECTED AND OBSERVED FREQUENCIES
true, independent, little
IF THE NULL HYPOTHESIS IS ______, THERE SHOULD BE _______ DIFFERENCES BETWEEN THE EXPECTED AND OBSERVED FREQUENCIES
false, large
THE GREATER THE ________ BETWEEN EXPECTED AND OBSERVED FREQUENCIES, THE _____ LIKELY THAT THE VARIABLES ARE ______ AND _____ LIKELY THAT WE WILL BE ABLE TO _______ THE NULL HYPOTHESIS
differences, less, independent, more, reject
X^2(OBTAINED) = Σ (fo - fe) ^2 / fe
calculation of chi square
FE = ROW MARGINAL X COLUMN MARGINAL / N
expected frequency formula of each cell
STEP ONE : MAKING ASSUMPTIONS AND MEETING TEST REQUIREMENTS
model : independent random samples
- level of measurement is NOMINAL
STEP TWO : STATING THE NULL HYPOTHESIS
ho : the two variables are INDEPENDENT
(h1 : the two variables are DEPENDENT)
STEP THREE : SELECTING THE SAMPLING DISTRIBUTION AND ESTABLISHING THE CRITICAL REGION
- the sampling distribution of sample chi squares are POSITIVELY SKEWED, with higher values of sample chi squares in the upper tail of the distribution
- the critical region is established in the UPPER TAIL OF THE SAMPLING DISTRIBUTION
DF = (R-1)(C-1)
degrees of freedom formula
STEP FOUR : COMPUTING THE TEST STATISTIC
x^2 (obtained) = Σ (fo - fe) ^2 / fe