Comm Health Final Flashcards

1
Q

The Null Hypothesis (Ho or sometimes NH)

A

null hypothesis refers to a general or default position: that there is no relationship between two measured phenomena, or that a potential medical treatment has no effect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Correlation coefficient

A

a measure of the linear correlation between two variables X and Y

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Value of correlation coefficient

A

between -1 and 1; closer to -1 or 1 is a stronger; 0 is no correlation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Positive correlation

A

graph with positive slope; as one variable increases so does the other or as one decreases so does the other - they both go the same way

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Negative correlation

A

graph with negative slope; as one variable increases the other decreases or as one decreases the other increases - they go opposite directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Strength of association

A

Value of r, can be -r or r; 0-0.25 is little if any association; 0.26-0.49 is weak; 0.7-0.89 is high; 0.9-1 is very high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

p value

A

usually set at 0.05; probability that findings are due to chance; this is to test the hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hypothesis testing

A

a statistical decision to reject or accept the null hypothesis based on probability (p) that is at a set significance level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Statistically significant

A

a value of p less than or equal to the set significant level means the results are statistically significant and you reject the null hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Not statistically significant

A

a value of p greater than the set significant level means the results are not statistically significant and you do not reject the null hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Type 1 statistic error

A

researcher rejects null hypothesis and concludes that a statistically significant difference exists when in fact no true difference is present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Type 2 statistic error

A

researcher concludes that no statistically significant difference exists and accepts the null hypothesis when in fact a significant difference does exist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Causes: type 1 error

A

large sample size; p value set too high (0.05 or greater); corrected by: randomly selected sample and good study design and set p value lower than 0.05

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Causes: type 2 error

A

too small a sample size; unrealistic measuring devices; imprecise research methods; corrected by: correction of causes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

t-test used in inferential statistics

A

statistical measure used when comparing hypothetical difference between TWO mean scores; NH for these tests - two unrelated groups are equal; looking to see if we can show that we can reject NH and accept alternative hypothesis - two NOT equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ANOVA test used in inferential statistics

A

statistical measure used when comparing hypothetical difference between THREE OR MORE mean scores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Chi-Square test used in inferential statistics

A

*attitudes - non-numbers; used to analyze discrete, nominally scaled data, and to test differences between frequency distributions; test independence of two categorical (descriptive) variables; helps one arrive at a p value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Standard of acceptability

A

p < 0.05; 1 out of 20 occurred by chance or it has nothing to do with the testing situation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Validity

A

degree that a study or procedure measures what it claims to be measuring; is it measuring how it claims it should?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Sensitivity

A

the ability of a test to correctly identify the presence of a disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Specificity

A

the ability of a test to identify the absence of a disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Reliability

A

the extent to which the method of measurement consistently performs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Null hypothesis

A

a question or statement to be answered that can be stated in a negative outcome; no benefit or significance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

research question or hypothesis

A

a question or statement to be answered; stated negatively or positively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Positive hypothesis

A

Brand X significantly whitens teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Negative (Null) hypothesis

A

No statistically significant difference exists between brand X and placebo; “NO SIGNIFICANT DIFFERENCE”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Dependent variable

A

the outcome of interest; change in it should be observed in response to some intervention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Independent variable

A

the intervention; what is being manipulated to change the outcome of interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Extraneous variables

A

not related to the purpose of the study BUT may influence the outcome; interfere with accurate interpretation and produce invalid research results

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Placebo

A

should have no positive or negative effects on subjects; should seem identical in every way to the real thing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Placebo effect

A

just knowing the desired effect produces it

32
Q

Calibrated examiners

A

should be educated the same on how to perform; unification of what they do - do things the same

33
Q

Intra-rater reliability

A

in one person; the one person is consistent in performance/ does the same all the time

34
Q

Inter-rater reliability

A

between more than one person; they all have consistent performance/ do the same all the time

35
Q

Hawthorne effect

A

they KNOW they are being watched and their performance is affected because of it - better

36
Q

Examiner bias

A

they have a reason for which way the experiment goes; prefer a certain side and make sure their side comes out positively; examining their own or being paid by a biased company

37
Q

Lack of control group

A

won’t have comparisons; less valid

38
Q

Single blind study

A

subject does not know but examiner does know what is being tested; sometimes knowing examiners accidentally persuade results

39
Q

Double blind study

A

both subject and examiner do not know what is being tested; *BEST outcome

40
Q

Sample

A

portion of the population that, if properly selected, can provide meaningful information about the entire population

41
Q

Simple random sample

A

gives every member of the population an equal chance of being selected; some mechanism of chance to choose them; no one is favored over another

42
Q

Systematic sample

A

every nth individual participates; ex: if you have 1000 and want 100 of that, every 10th person

43
Q

Stratified random sample

A

random sample carried further into sub groups; some from each group; if you want to be sure to cover such things as age, gender, income level, education levels, etc.

44
Q

Biased sample

A

can lead to misleading results; sample chosen ensures results consistent with desired outcome

45
Q

Judgement sample (Purposive)

A

choosing with a purpose for choosing certain groups; someone who knows the population chooses a sample to represent the population; risk of bias

46
Q

Convenience sample

A

at convenience of researcher; simplest method; little concern for representativeness; may not be applicable to general population

47
Q

Sampling error

A

occurs when a sample measurement is different from the population measurement; selecting sample not perfectly matched to represent entire population; can lead to inaccurate conclusions about the population

48
Q

General sampling rules

A

30 subjects; study done for at least 6 months; should be of a meaningful population

49
Q

Statistics

A

the science that deals with the collection, tabulation, and systematic classification of data

50
Q

Types of data

A

Qualitative (categorical); Quantitative (continuous)

51
Q

Qualitative

A

uses descriptive terms to measure or classify something; nominal, dichotomous, ordinal

52
Q

Quantitative

A

uses *numerical values to describe something; interval, ratio

53
Q

Nominal

A

variables with a name, that have no particular order; ie: puppy types, blood types, eye colors

54
Q

Dichotomous

A

variables that only have TWO categories or levels; ie: gender: female or male, state of living: dead or alive

55
Q

Ordinal

A

variables whose categories can be ordered or ranked, but the spacing between values may not be the same across the levels of variables; ordered but not proportionally ratioed; ie: education level (elementary, freshman, sophomore, junior, etc), pain level, cancer stages, *decay classifications (1-6)

56
Q

Interval

A

points are equally spaced along the scale and the difference between the two points is meaningful (as opposed to ordinal scales); ie: temperature, IQ, pain scale 1-10, body length of infant; NO meaningful zero point

57
Q

Ratio

A

ratios between points has meaning; Zero does count, can use “twice as much” rule; ie: age, weight, height, time, BP, distance, pulse, etc

58
Q

Graphs

A

to express data; bar, histogram

59
Q

Bar Graph

A

used to present categorical variables, bar for each category with spaces between to represent discrete nature of data

60
Q

Histogram

A

similar to bar graph, but bars appear side by side (touching)

61
Q

Measures of central tendency

A

single value to describe a set of data by identifying the central position within that set of data; mean, median, mode

62
Q

Mean

A

arithmetic average of scores; most common measure of central tendency; particularly susceptible to extreme values; most useful and most familiar; always center of balance of distribution in a symmetrical distribution

63
Q

Median

A

point of distribution with 50% of scores falling above it and 50% falling below it; NOT affected by extreme values; Midpoint: when total number is odd, median is midpoint; when total number is eve, take two middle scores and average

64
Q

Mode

A

Most frequent score in a distribution; affects skew of graph, you CAN have 2 modes (bimodal), if everything is equal you have NO mode; least used of the measures of central tendency

65
Q

Type of variable: Nominal

A

Best measure of central tendency: Mode

66
Q

Type of variable: Ordinal

A

Best measure of central tendency: Median

67
Q

Type of variable: Interval/Ratio (not skewed)

A

Best measure of central tendency: Mean

68
Q

Type of variable: Interval/Ratio (skewed)

A

Best measure of central tendency: Median

69
Q

Measures of dispersion (spread)

A

Range; Variance; Standard of Deviation; used to describe how much variation is present in a sample

70
Q

Range

A

difference between the highest and lowest scores in a data set; simplest measure of a spread; Range = Maximum value - Minimum value; ie: 95K-12K=83K; smaller (narrow) range is better because a large range means the mean is not as representative of the data

71
Q

Variance

A

represents the average distance of each score from the mean

72
Q

Standard deviation

A

the square root of the variance; a measure of the spread of scores within a set of data; appropriate when data isn’t skewed or has outliers;

73
Q

Bell curve

A

most of the time standard deviation works within a normal bell curve distribution

74
Q

Positive (RIGHT) skew

A

outliers create positive skew when most scores are lower but one or two are higher ——–>

75
Q

Negative (LEFT) skew

A

outliers create negative skew when most scores are higher but one or two are lower <——-

76
Q

Skewed distribution

A

distribution of scores is NOT symmetrical

77
Q

Normal distribution

A

bell curve; 68-95-99.7 rule; the majority of the scores always falls within +1 or -1. That is a given. It will always be true regardless of the value of the standard deviation