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#1




Nominal vs Ordinal vs Interval vs Ratio
I am not able to recognize whether the data is Nominal, Ordinal, interval or ratio. I have read the definitions of each in HY, BRS, Kaplan and the Internet but I cannot identify the data type and miss the question on choose the statistical test.
Any help will be highly appreciated. TIA 
#2




nominal> no order, category labels (male or female, religious status, place of birth)
ordinal> logical or ordered relationship across the value, some degree of difference between categories (no stress, mild stress, moderate stress, severe stress, extreme stress) scale> interval scale(unit) (10'F, 20'F) , no true zero point (eg., 0'F does not indicate that there is no temperature) > ratio scale , true zero point (eg., 0 year old at birth), length, weight and income 
#3




i found this in another forums.....hope this shall clear the concept
1"Interval variable" (values from where we can drive their "Mean") e.g. measurements of B.P, Weight, Cholesterol levels etc 2"Nominal variable" ( different categories or "GROUPS") e.g. *Gender is a Nominal that has Two Groups (Male and Female) *AGEis a Nominal that we can have either TWO groups (Elderly and Middle age) or THREE Groups(Elderly, Middleage and Children) etc *Racea Nominal that can have many groups Two groups (African Americans and Latino) Three groups(African Americans, Latino and Asian) and so forth e.g. *"GENDER"(Men and Women)............................................ ........(Single Nominal) *"GENDER"(Men and Women) n "RACE"(Caucasian and African)....(Two Nominals ) e.g we compare Blood Pressure measurements *INTERVAL variable ("MEANS" of B.P measurements) *NOMINAL variable ("GROUPS" ) so to compare MEANS of B.P. b/w two are more groups we do these tests tTest: 1 Interval (Blood pressure Means) 1 Nominal with "ONLY TWO GROUPS" e.g. comparing the BP means b/w (Latinos) and (African Americans) *for a tTest it will be a wrong statement to say e.g comparing B.P means b/w (Latinos), (African Americans) and (Asians)....*got 3 groups Now what's the difference B/W tTest and ANOVA tTest>ONLY TWO Groups comparison ANOVA>TWO Groups or more than Two Groups comparison NOTE:these two will give u the Identical results if comparing "TWO Groups" tTest................... 1 Interval and 1 Nominal with TWO Groups Oneway ANOVA.....1 Interval and 1 Nominal with TWO Groups and for the above reason they rather use Oneway ANOVA when more than two groups are there to be compared e.g as above comparing B.P means b/w (Latinos), (African Americans) and (Asians).......3 groups Twoway ANOVA: 1 Interval 2 Nominal e.g. Gender (Men and Women) *AND Race (Caucasians and African Americans) >we do these tests to see If there is a Difference b/w groups ? tstatistics (tTest) and fstatistics(ANOVA) will be compared to get a pvalue If pvalue = 0.05 or less it is said to be "Statistically Significant' and we say that there is a Difference in these Groups. Chisquare: we compare b/w "TWO NOMINAL" (with ANY # of GROUPS) (Note; we are not using any Interval variable here , just the NOMINAL data) best example...."Testing Drug Efficacy" First Nominal........(New drug group) and (Placebo group) Second Nominal ...(Recovered group) and(Not recovered group) ***I think this is all u have to do is recognize what kind of data is presented , how many Nominals, How many groups and If Interval variable is used or not? 1 Interval and 1 Nominal (Two Groups).......................tTest or Oneway ANOVA 1 Interval and 1 Nominal (More than Two groups)........Oneway ANOVA 1 Interval and *2 Nominal (many groups)....................Twoway ANOVA .....................*2 Nominal (any# of Groups).................Chisquare even visit this link Types of scales and Stats tests?
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#4




Thanks anomali... this is what I was looking for... spelled out clearly....
To add to this few more Q....
TIA 
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