Statistics interview questions

Question

I am looking for some statistics (and probability, I guess) interview questions, from the most basic through the more advanced. Answers are not necessary (although links to specific questions on this site would do well).

Answer 1

Not sure what the job is, but I think "Explain x to a novice" would probably be good-

a) because they will probably need to do this in the job

b) it's a good test of understanding, I reckon.

Answer 2

Standard Q where I work is along the lines of:

Have a look at this output of a multiple logistic regression from a statistical package you claim to have used (preferably one we use too). XXX is the independent variable of principal interest. How woud you interpret the results for a colleague with knowledge of the subject matter but no formal statistical training? (If necessary prompt for separate interpretation of point estimate, CI, p-value).

Answer 3

You might also want to reflect on whether the interview is the best medium for measuring the construct of interest. If you want to measure prior knowledge of probability or statistics, you might be better off relying more on a written test. You can ask more questions, and thus increase reliability of measurement. It's more standardised both in administration, and in scoring. And once the instrument is developed, it probably uses fewer resources to administer.

You could then use the interview as a more focussed tool looking at factors such as verbal and interpersonal skills.

Answer 4

Two questions I've been asked:

1) You fit a multiple regression to examine the effect of a particular variable a worker in another department is interested in. The variable comes back insignificant, but your co-worker says that this is impossible as it is known to have an effect. What would you say/do?

2) You have 1000 variables and 100 observations. You would like to find the significant variables for a particular response. What would you do?

Answer 5

Here is a big data set. What is your plan for dealing with outliers? How about missing values? How about transformations?

Can they deal with real-world data?

Answer 6

I was asked once how I would explain the relevance of the central limit theorem to a class of freshmen in the social sciences that barely have knowledge about statistics.

Answer 7

How do you numericize something that is not numerical?

Example, "Automatic Feature Extraction for Classifying Audio Data"

Rationale: Can they figure out how to analyze something statistically that is not already in a big table?

Answer 8

I often ask "how would you define/explain what forecasting is?"

Answer to that type of very general question helps me to see if people are connected to a particular case of forecasting. There is not a right answer but answering this synthetically during an interview is not always easy:)

Answer 9

How do you prevent over-fitting when you are creating a statistical model?

Good answer: cross-validation

Answer 10

For an observational data context:

Consider this regression model applied to this substantive problem. What, if anything, in it can be interpreted causally? [Further probe] What would you need to learn to change your opinion?

Answer 11

Here is a TinkerToy set. Show me how Euclidean distance works in three dimensions. Now show me how multiple regression works.

Can they explain how statistics works in the physical world?

Answer 12

How will you count the number of sandal wood trees in Bangalore ?

Answer 13

We are running a customer service centre. We are getting 1 million calls per month. How do we reduce it to ten thousand ?

Answer 14

While doing the variance analysis of quantitative variable, sometimes it found that frequency of the variable are very high (>5) then we use the Fisher's exact test to find independence of the variable.