hsci 207 research > Quantitive analysis > Flashcards

Quantitive analysis Flashcards

(43 cards)

Study These Flashcards
1
Q

why is statistics important?

A
  • way to describe and measure biology
  • allows us to estimate an unknown quantity using our sample
  • test hypotheses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

is stats math?

A

kinda? helps us to define what we know, how we know it and how strong the evidence is

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

what do we use descriptive stats for

A

summarize and describe the data
describe patterns
tables, graphs and charts
- the first step of making inferences

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

what are the 4 types of descriptions of data and their two categories

A

Categorical
1. nominal
2. ordinal

continuous
1. interval
2. ratio

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

What is nominal data?

A
  • at type of categorical data
    1. non - ordered categories
  • sex
  • blood type etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is ordinal data ?

A

type of categorical data
- ordered categories
eg: house hold income - lowest to highest
eg: age

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

how do we display nominal data?

A
  • frequency tables
  • bar graphs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how do we display/describe continuous data?

A
  1. frequency table
  2. histogram
  3. parameters - mean, median etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a frequency table?

A

Create artificial groups and report the frequency
* e.g. age
* This is not very informative and throws out information

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

what does a histogram show?

A

the shape of the data,

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

how to describe continuous variables?

A
  1. when measuring central tendency
    a)mean
    b) media
    c)mode
  2. measuring of variability or spread
    a)range
    b)percentiles
    c) variance/standard deviation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is a central tendency?

A

the average distribution.continuous variable
summarizes the data with a single value

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

what can the mean be distorted by?

A

outliers

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

what is the median?

A

middle of data
order from smallest to largest and average two middle points

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

what is the mode?

A

number that occurs most often in the data
can be more than 1
not impacted by outliers

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

when to use mode, median and mean

A

mode - rare
mean - if your sample is normal - bell
median - if your sample is skewed

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

what is the range?

A

smallest to largest values

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

what are the percentiles? -hard

Study These Flashcards
A
  • a measure of the dispersion for one variable that indicates the % of cases at or below a score or point
    eg: the median is the 50th percentile
    eg: 25th percentile is the value at which 25% of the distribution have that value or a lower one
    often report quartiles - 25th, 50th, 75th
19
Q

what is standard deviation/variance?

Study These Flashcards
A
  • the measure of dispersion for one variable that indicates an “average distance” between the values and the mean
20
Q

what is generally used to show continuous data visually?

21
Q

What do boxplots show? - parts of it

Study These Flashcards
A
  • the median
  • the IQR - intervals q1 q2 etc
  • the range or the outliers
22
Q

if the median is the centre of a boxplot what does it mean

Study These Flashcards
A

that you have a bell-shaped curve

23
Q

what can boxplot diagrams be used for?

Study These Flashcards
A
  • to compare different groups
24
Q

what are the types of prevalence?

Study These Flashcards
A
  • point prev
  • period prev
  • lifetime prev
25
what is incidence density/ rate
the number of new cases in a given time period divided by total person-time of follow-up (sum) USed for longitudinal cohort studies - each person contributes time based upon how long they were followed -
26
what happens when individuals are censored in data ?
we exclude any data on them that was gathered after the censoring point, if any
27
what is the unit for incidence density
generally per 100 person-years because you times the number you get by 100
28
what does mortality rate show?
- how many people die from a disease in a given time
29
what does case fatality rate mean
CFR = the proportion of people WITH the disease who die within a given time, again usually one year
30
what is a issue with MR's and CFR's? `
we do not know if the number is high or low except if comparing to other disorders - do not always know how many people have the disorder One way around this issue is to look at death rates for a specific disorder in relation to deaths from all causes...
31
What is the proportional Mortality Rate? PMR
the number of deaths due to a disorder in a given time divided by ........... number of deaths from all disorders - makes sense only when we compare the PMR from one disorder to another disorders PMR
32
How can the PMR for a disease increase over time? 2 reasons
1. more people may be contracting and dying from the disorder 2. fewer people may be dying from other causes
33
What is the Standardized Mortality Rate?
the ratio of the number of observed deaths from a given cause in a given time to the expected number of deaths - this measure does not have to be compared to others
34
how do we interpret SMRs? Standardized mortality rates
- an SMR less than 1 = people with the disorder are dying lower than the expected rate - an SMR more than 1 = higher than the expected rate
35
when does using the general population not make sense as a reference group?
when comparing groups with different age structures - need to use - age-standardized mortality rates
36
what do measures of impact find? m
how dangerous the disease is - relative risk or odds
37
what is the relative risk
the ratio of... 1. the risk of death in the exposed group - a divided by a+b 2. the risk of death in the unexposed group - c divided by c+d relative risk is the ratio of these two risks exposed risk divided by unexposed risk
38
what are the limitations of relative risk?
the relative risk is the same regardless of prevalence of the disorder
39
what is relative risk reduction RRR
improvement as a percent relative to the comparison group risk (treatment) - risk (control) divided by............ risk (control)
40
Absolute risk reduction ARR
- decrease in the risk of the treatment group compared to the control group risk treatment - risk control
41
What is the number needed to treat? NNT
the number of people who need to be treated to have one additional positive outcome NNT = 1/0.1 = 10 eg: need to treat 10 people for one cure
42
What is the odds ratio?
this is used in case-control studies to assess the relationship between the exposure and the disease - the ratio of the odds of exposure among the cases compared to the odds of exposure amount the controls
43
what does PICO stand for?
population intervention comparison outcome
hsci 207 research
flashcards
Decks in class (12)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions