Variables - Isfahan University of Medical Sciences · INS12 344 Ranking scale A nominal scale with...

Variables

1

4

Lecture Objectives

What is a variable?

Why discuss about variables?

Types of data

role of variables

نام متغيرنقش متغير

واحد نوع متغير

اندازه گير ي

روش

اندازه گير كيفي كمي ي

What Is a Variable ?

INS344 6

A characteristic varies

It is recorded in our study

http://online.indstate.edu/courses/INS344-301/




روش


Types of Data

INS344 8

Continuous (پيوسته)

Discrete (گسسته)

Ordinal ( رتبه ای)

Nominal ( اسمی)

Numerical ( کمی)

Categorical ( کيفی)


Scales of Measurement

علمی -1

غ ق جمع -2

جامع -3

رده کافی -4

مناسب -5

رده ی تعريف شده -6

قوی -7


INS344 10

Nominal

Ordinal

Interval

ratio Numerical ( کمی)



Nominal

Ordinal

Interval

ratio

INS344 11

Classificatory

Names

Labels


INS344 12

Ranking scale

A nominal scale with an implicit order

relationship among the measurement

The difference between two adjacent

categories is not the same through out

the scale

Nominal

Ordinal

Interval

ratio


INS344 13

The unit of measurement and the zero

point ) starting point ) …..

The zero point does not mean the

lack of the characteristic

Nominal

Ordinal Interval ( فاصله ای)

ratio


INS344 14

A true or absolute zero

The ratio between two values is a

meaningful measure of the relative

magnitude of the two measurements

Nominal

Ordinal

Interval Ratio (نسبتی )



INS344 15

Nominal

Ordinal

Interval

ratio Numerical ( کمی)



Examples …

INS344 16

•Drug type

•Hb concentration

•Prevalence of Hepatitis B

•Amount of pure drug in different types of Ampicillin

•Number of deaths in year 1390

•Mortality

•Blood pressure





روش


Types of Data

INS344 19

Continuous (پيوسته)

Discrete (گسسته)

Ordinal ( رتبه ای)

Nominal ( اسمی)

Numerical ( کمی)






روش


Roles of Variables

INS344 21

Main variable

Independent variable

Dependent variable

Background variable

Interventing variable


INS344 22

A B

•Independent variable

•Dependent variable

•Background variable

•Extraneous variable

•Confounding variable


INS344 23

A B

•Independent variable (مستقل )





Exposure

Treatment

Risk factor

Cause

Study factor

predictor


INS344 24

A B

•Independent variable •Dependent variable (وابسته)




Outcome

Disease

Effect

Event

Response

Criterion

Exposure

Treatment

Risk factor

Cause

Study factor

predictor


Chocolate

consumption

Nobel

prizes

NEJMon1211064

UV Airborne pathogen

INS344 27

A B


•Dependent variable •Background variable ( زمينه ای)



Background variable


INS344 29

L - DOPA Parkinson





Patients attitude


INS344 30

Cigarette Stroke





Sex


Examples …

INS344 31

•Bladder cancer . Vit A

•MI . HLP

•Lung cancer . smoking

•IQ . Fe

•Thyromegaly . Water iodine

•Blood group . Diabetes


INS344 32

A B

C



•Background variable •Extraneous variable (مزاحم)



INS344 34

HLP MI

Smoking






INS344 35

Hot tea E. cancer

Smoking






INS344 36

A B

C




•Extraneous variable •Confounding variable (مخدوشگر)


INS344 38

coffee MI

smoking






INS344 39

Opium IQ

smoking






INS344 41

A B

C

Intermittent ( واسطه ای)


INS344 42

gender Coronary

disease

smoking



INS344 43

diet Coronary

disease

LP



جدول متغير ها

INS344 45

•Numbers of variables

•Qualitative Quantitative


INS344 46

We think that Isfahanian

multipara women are at risk of

Anemia more than usual.

Anemia / Number of past pregnancies

Poor culture / Gender / City


Learned or Not ?

INS344 47

What is a variable?

Why discuss about variables?

Types of data

Scales of measurement

role of variables

Movie


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