Ask 10 general questions to the text. 7. Answer the following questions:

7. Answer the following questions:

· What are the three Ws of statistics?

· How important are variables to your analysis?

· What are samples made of?

· What do you need to look at while examining the cases in your sample?

· What will enable you to distinguish the samples?

· How can variables be classified?

· What are categorical variables?

· What are numerical variables?

· How are variables classified according to a hierarchy of measurements?

· How can data be classified according to the actual values?

8. Write out the definitions of variables from the texts:

Categorical –

Numerical –

Nominal –

Ordinal –

Interval –

Ratio –

1. Give examples of these variables.
2. Summarize the contents of the text in 10 – 15 sentences. Use the expressions:

I’d like to say a few words about …

I’d like to draw your attention to …

It’s important to note that …

One must mention …

Summing up …

* * * * *

Don’t put all your data into one basket!

An animal science researcher came to me one time with a data set he was so proud of. He was studying cows and the variables involved in helping determine their longevity. He came in with a super-mega data set that contained over 100,000 observations. He was thinking “Wow, this is gonna be great! I’ve been collecting this data for years and years, and I can finally have it analyzed. There’s got to be loads of information I can get out of this. The papers I’ll write, the talks I’ll be invited to give... the raise I’ll get!” He turned his precious data over to me with an expectant smile and sparkling eyes.

But after looking at his data for a few minutes I made a terrible realization — all of his data came from exactly one cow. With no other cows to compare with and a sample size of just one, he had no way to even measure how much those results would vary if he wanted to apply them to another cow. His results were so biased toward that one animal that I couldn’t do anything with the data. After I summed up the courage to tell him, it took a while to peel him off the floor. The moral of the story, I suppose, is to find a statistician and check out your big plans with her before you go down a cow path like this guy did.