Exam 1 Flashcards

Endocrine system

1
Q

Study designs

A

Non- human and human studies

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

Statistics

A

the collection, organization, analysis, visualization and interpretation of numerical data

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

The big picture

A

producing data, exploratory data analysis, Probability, inference. [Population-> sample -> statistics -> parameters -> Population]

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

study designs

A

Non-human studies, human studies

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

non- human studies

A

experimental: traditional bench research

Non- experimental: field studies

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

human studies

A

experimental: randomized controlled Trials

Non- experimental: Observational- generally only reveals correlation.”correlation does not imply causation”

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

Observational studies

A

Cohort Study: follow a group of subjects over time, disease incidence.
Case- control: subjects selected on the basis of disease status, “do the diseased differ from the healthy in other ways?”
Cross-sectional study: simultaneously assess disease/exposure in a cross- section of the population.

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

Randomized control trials

A

Collect a random sample
– Subjects randomized into treatment or placebo group.
– Single- or double-blinded
– Very large samples, hundreds, thousands, etc.
– Can imply causation
– Gold standard for study design

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

Data

A

pieces of information about individuals organized into variables.

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

variable

A

a particular characteristic of the individual

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

Dataset

A

a set of data identified with particular circumstances. Datasets are typically displayed in tables, in which rows represent individuals and columns represent variables.

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

quantitative variable

A

takes a numerical value and represents some kind of measurement.

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

Categorical variable

A

: takes a category or label value and places an individual into one of several groups.
Categorical variables are sometimes called qualitative variables.

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

Exploratory Data Analysis (EDA):

A

how we make sense of the data by converting them from their raw form to a more informative one.

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

EDA consists of

A

• organizing and summarizing the raw data,
• discovering important features and patterns in the data and any striking deviations from those
patterns, and then
• interpreting our findings in the context of the problem

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

Distribution

A

what values the variable takes and how often the variable takes those values.

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

Graphical display of categorical variables

A

pie chart or bar chart, supplemented by numerical summaries (category counts and percentages).

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

Histogram

A

a graphical display of the distribution of a quantitative variable. It plots the number (count) of observations that fall in intervals of values. The histogram is the best graph to use to display the distribution of a quantitative variable.variable on x axis, frequency on y axis

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

Stemplot

A

a graphical display of the distribution of a quantitative variable. It has additional unique
features, such as preserving the original data and sorting the data.

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

4 features of a distribution include:

A
  1. Center
  2. Spread
  3. Shape
  4. Outliers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

2 dimensions of the shape of a distribution include:

A
  1. Symmetry/skewedness

2. Peakness/modality: Number of peaks (modes) the distribution has

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

Peakness/modality: Number of peaks (modes) the distribution has

A

a. Unimodal distribution: one with one mode around which the observations are concentrated.
b. Bimodal distribution: one with two modes around which the observations are concentrated.
c. Uniform distribution: one that is kind of flat.

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

Symmetry/skewedness:

A

a. Symmetrical (normal) distribution: the left and right sides of the distribution mirror each other,
with one peak (mode).
b. Skewed right distribution: the right tail of the histogram (larger values) is much longer than the
left tail (small values).
c. Skewed left distribution: the left tail of the histogram (smaller values) is much longer than the
right tail (larger values).

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

Midpoint:

A

the center of the distribution, or the value that divides the distribution so that approximately
half the observations take smaller values, and approximately half the observations take larger values.

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

Outliers

A

observations that fall outside the overall pattern

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

Center

A

of the distribution can be described as the most commonly occurring value in the distribution

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

Mean

A

describes the center as an average.

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

Weighted average

A

the mean is computed by “weighting” each value by its frequency. Some values will have more weight than others.

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

Median:

A

the middle value in a distribution (50th percentile) or the POINT above and below which 1/2 of the scores fall. Because the median is not affected by extreme scores, it is most appropriate for skewed distributions of quantitative data

30
Q

Mode:

A

the most commonly occurring value in a distribution.

31
Q

Spread

A

(also called variability) of the distribution can be described by the approximate range covered
by the data. Three measures of spread are: range, interquartile range, and standard deviation.

32
Q

Range

A

the distance between the smallest data point (min) and the largest one (Max).

33
Q

Interquartile Range (IQR)

A

measures the variability of a distribution by giving us the range covered by
the middle 50% of the data. IQR = Q3 - Q1

34
Q

Five Number Summary:

A

the combination of all five numbers (min, Quartile 1, Median, Quartile 3, Max)
that provides a quick numerical description of both the center and spread of a distribution.

35
Q

Boxplot

A

graphically represents the distribution of a quantitative variable by visually displaying the fivenumber summary and any observation that was classified as a suspected outlier using the 1.5(IQR) criterion. Boxplots are most useful when presented side-by-side for comparing and contrasting distributions from two or more groups

36
Q

Standard deviation

A

measures the spread by reporting a typical (average) distance between the data points and their average (mean).

37
Q

Properties of the SD

A

(1) It should be paired as a measure of spread with the mean as a measure of
center; (2) the only way, mathematically, in which the SD = 0, is when all the observations have the
same value (Ex: 5, 5, 5, … , 5), in which case, the deviations from the mean (which is also 5) are all 0; (3)
it is strongly influenced by outliers in the data.

38
Q

The Standard Deviation Rule

A

• Approximately 68% of the observations fall within 1 standard deviation of the mean.
• Approximately 95% of the observations fall within 2 standard deviations of the mean.
• Approximately 99.7% (or virtually all) of the observations fall within 3 standard deviations of the
mean.

39
Q

Role-Type Classification

A

When we look at relationships between two variables, each variable can be described in terms of it’s proposed role in the relationship, and the type of information associated with that variable, which determines it’s categorical designation. While these designations DO NOT imply causality, designating our variables as either explanatory, or a response helps us understand the nature
of, or our underlying beliefs about the relationship.

40
Q

Role

A

Explanatory or Response

41
Q

Type

A

categorical (C) or quantitative (Q)

42
Q

Categorical variable(high)

A

mutually exclusive categories exist, Eg. gender, treatment group
also called factor variables in R
They are discrete or countable not measured

43
Q

Quantitative

A

something is measured or counted. Eg. Height, family size

44
Q

Independent Variable

A

Another way of describing the explanatory variable. Despite what the terms “Independent” and “dependent” would seem to suggest, they do not
necessarily mean that a causal relationship exists.

45
Q

Dependent Variable:

A

Another way of describing the response variable.
Despite what the terms “Independent” and “dependent” would seem to suggest, they do not
necessarily mean that a causal relationship exists.

46
Q

non- EBM studies

A
Non- Evidence Based studies: 
Non- medical human subject research:
- research to understand basic science
Animal & Cell culture studies:
- Mice=/people
-cells from other people ≠ people
47
Q

The Conditions for Concluding Cause!

A

To conclude that Event A causes Event B

  1. Event A and Event B must be correlated
  2. Event A must precede Event B
  3. All other explanations of the relationship between Event A and Event B must be ruled out
48
Q

Interval(sub)

A

Subcategory of quantitative Variables
“0” = placeholder. A quantity still exists at zero.
Math properties: addition and subtraction, NO multiplication or division
EX: acidity(pH), intelligence (IQ)

49
Q

Ratio(sub)

A

Subcategory of quantitative Variables
“0” = total absence of thing measured
Math properties: addition, subtraction, multiplication, division
Examples: Wealth(dollars), Weight(kg), height (m) measures not counts

50
Q

quantitative variable(High variable)

A
also called continuous or scale.
something measured using a standard(metter,sec,gram)
between any two values=infinity.
Involves decimals
"0" may or may not mean no amount
51
Q

Nominal variables(sub)

A

Categories are identified by name only.

  • types of diseases
  • Gender (male, female, etc.)
  • ethnicity
52
Q

Ordinal variable(sub)

A

Categories have name and an order.

  • 1st, 2nd, 3rd
  • Gold, silver, bronze
  • small medium, large,
  • pre/post treatment
53
Q

Confounding Variables

A

variables that can ruin your experiment by producing useless results that falsely suggest correlation or causation.

  • randomization
  • stratification, blocking & matching pair designs
  • Standardization: Eliminating the influence of potential confounding through division and multiplication
54
Q

Bins on histogram

A

How many variables are grouped to be plotted together. (= not included, [= included

55
Q

c -> c

A

two way table

56
Q

C -> Q

A

Bar & pie, side by side boxplots

57
Q

Q -> Q

A

scatterplots, correlation and regression

58
Q

Sampling approachs

A

simple random, random, cluster, stratified, multistage sampling

59
Q

simple random

A

All individuals/ groups have same probability

60
Q

random

A

All individuals, but not all groups have same probability

61
Q

cluster

A

Natural clusters are selected

62
Q

stratified

A

Random sampling within existing strata

63
Q

multistage sampling

A

Combining the above sequentially

64
Q

Blocking

A

arranging subjects into similar blocks prior to randomizing into experimental legs.

65
Q

Matched-pairs

A

Pre/Post (before and after), Similar subjects are paired

66
Q

Crossover

A

Placebo subjects later cross over to treatment leg. Treatment leg later cross over to placebo leg.

67
Q

aggregated

A

aggregated data is misleading, and is caused by a lurking variable

68
Q

reaggregated

A

correct data that is modified to exclude the lurking variables

69
Q

Simpson’s Paradox

A

A trend that is reversed in direction, when the data are considered in either an aggregated form or a disaggregated form. The trend in the aggregated data is misleading, and is caused by a lurking variable that is only visible when examining the disaggregated data.

70
Q

Extrapolation

A

Making predictions based on values of an explanatory variable that are outside those used to establish the relationship. Generally considered not valid.

71
Q

modifications after sampling

A

blocking, matched pairs, crossover