HCM 360- Section 4 Flashcards
inferential statistics
used to draw conclusions about what’s likely true in a larger population based on findings from a sample
Descriptive Statistics
characterize sample itself
Define Ordinal Measurement
data that are measured by categories imply order (i.e. clothing size, military rank); consistent in direction; defines a total preorder of objects; the scale values themselves have a total order
Define ratio measurement
data that have differences that are meaningful and relate to some true zero point (i.e. weight, height, age); most common scale of measurement
Define interval measurement
data if the difference between values have meanings (i.e. temperature)
Define Nominal measurement
data used when each case is classified into one of a number of discrete categories i.e. color, political party, gender; “Naming” level
What are the measures of central tendency?
Mean, Median, and Mode (NOT RANGE)
Define Mean
the arithmetic average of a set of values, or distribution; most common measure of central tendency; can be applied to interval data
Define Median
score that divides distribution into two equal parts so that half the cases are above it and half are below it; represents exact center/middle of distribution; appropriate for variables at ordinal level; described as the number separating the higher half of a sample, a population, or a probability distribution, from the lower half. The value below, which lies 50% of the data; can be applied to ordinal, interval data; not nominal
Define Mode
the values that occurs with the greatest frequency in a set of data; can be applied to nominal, ordinal, interval data
Considering the numbers 3,10,4,9,5,2 and 9, what is the median?
5
What are the measures of variation?
variance, standard deviation, and range
Define Range
the difference between the largest and smallest values in a given set of data; measure of variation
Define Variance
the amount to which each object differs
Define Standard Deviation
describes the variability of the sample; how much participants vary or differ from each other
Skewness
a skew is positive if it is skewed to the right. A skew is negative if it is skewed to the left.
Normal distribution
a bell curve
Collectively exhaustive
when a set of data includes all of the possible observations without missing any values. An example would be choosing African American and White when there are Hispanics in a data set.
Mutually exclusive
an observation is assigned one and only one category. Example would be hospitals grouped by type.
T-test and Simple one-way ANOVA
The t-test is used when determining if two averages or means are the same or different. The ANOVA is preferred if comparing three or more averages or means. A t-test has more odds of committing an error the more means are used which is why ANOVA is used when comparing two or more means.
Linear Regression
an approach for modeling the relationship between a scalar dependent variable y and one or more explanatory variables (or independent variables) denoted X
Dr. Evens was surprised that many of his participants scored much lower than expected on his post-test. When he observed a significant increase in score on the pre-test, he was cautious in attributing the effect to his treatment alone. Which of the following threats to internal validity was Dr. Evans concerned about? A) Instrumentation B) Selection C) Regression D) Testing
C) Regression
When a set of data includes all of the possible observation without missing any values, it is know as
Being collectively exhaustive
Which of the following variables is an example of the nominal level of measurement? A) Rank in grad class B) Gender C) age of students D) Amount of money earned
B) Gender
Null hypothesis
states an assumption to be tested; rejecting a null hypothesis after observing a test statistic which exceeds the critical value at the .05 level means that there is a 5% chance that the null hypothesis is actually true
Non-directional hypothesis
a non-directional research hypothesis reflect a difference between groups, but the direction of the difference is not specified. We do not suppose that one is higher than the other.
Directional hypothesis
a direction research hypothesis reflects a difference between groups, and the direction of the difference is specified. This represents an equality but not of a specific nature
If Dr. Robinson rejects the null hypothesis after observing a test statistic which exceeds the critical value at the .05 level, there is ________
A 5% chance that the null hypothesis is actually true
Type I Error
The probability of rejecting a null hypothesis when it is true. Usually 0.05 or p < .05. Whenever p-value is less than alpha, always reject the null/ accept the research.
Type II Error
The probability of failing to reject a null hypothesis when it is false. Example: There really is a significant difference in a given population, but you do not find the difference in your sample and thus determine that there is no significant difference (thus you fail to reject a false null). As your sample characteristics become closer to the population, the probability that you will accept a false null hypothesis decreases. Whenever the p-value is higher, you reject the research hypothesis and accept the null.
Which is an example of ordinal scale measurement?
Freshman (in school; sophomore, junior, senior)
