SAS Certified Specialist: Base Programming Using SAS 9.4 Interview Questions

While some interviewers have their style of inquiry, most job interviews follow a set of questions and answers (including some of the most often-asked behavioural interview questions). Here are some of the most often asked interview questions, along with some of the greatest responses. To begin, consider the following expert tips for SAS Certified Specialist: Base Programming Using SAS 9.4 interview preparation:

1. In a SAS programme, what is the purpose of the output statement?

• The OUTPUT command can save summary statistics in a SAS data set. This data can subsequently be utilised to generate customised reports or save historical data about a procedure.
• Options in the OUTPUT statement can be used to
• Specify the statistics to save in the output data set, the name of the output data set, and the percentiles not generated automatically by the CAPABILITY process to compute and save.

2. In a SAS programme, what is the purpose of the Stop statement?

The stop statement causes SAS to immediately stop processing the current data step and begin processing after the current data step is complete.

3. What is the difference between the data statement’s drop = data set option and the set statement’s drop = data set option?

Use the drop = data set option in the set statement if you don’t want to process specific variables or have them appear in the new data set. If you want to process specific variables but don’t want them to show in the new data set, use the data statement drop = data set option.

4. How does reading data from an external file vary from reading data from an existing data set?

The primary distinction is that when using the SET command to read an existing data set, SAS keeps the variable values from one observation to the next. Only the observations are read when the data is read from an external file. If the variables are to be used, they must be re-declared.

5. In SAS, how many different data types are there?

In SAS, there are two categories of data. Characters and numbers are two types of data. Dates, on the other hand, are treated as characters, even though they have implicit roles.

6. What’s the difference between using the “+” operator and utilising the sum function?

The sum of non-missing parameters is return by the SUM function, whereas the “+” operator returns a missing value if any of the arguments are missing.

7. How do PROC MEANS and PROC SUMMARY differ from one another?

Only when a BY statement is used, and the input data has been previously sort (using PROC SORT) by the BY variables does PROC MEANS produce subgroup statistics.

PROC SUMMARY generates statistics for all subgroups in one run, providing you all the information you’d obtain from sorting a data set by the variables that define each subgroup and running PROC MEANS many times. Your result from PROC SUMMARY has no information. As a result, you’ll need to establish a new DATA SET with the OUTPUT command and then use PROC PRINT to display the computed statistics.

8. Give an example of when SAS fails to automatically convert a character value to a numeric value.

Assume that the variable PayRate has a value that starts with a dollar sign ($). The dollar symbol prevents SAS from automatically converting the values of PayRate to numeric values. The values aren’t able to be translated into numbers. When conversions occur, it is always ideal to include INPUT and putting functions in your programmes.

9. What’s the difference between doing something while and doing something until?

The DO WHILE phrase is evaluate at the top of the DO loop, a significant difference between the DO UNTIL and DO WHILE statements. The DO loop never executes if the expression is false the first time it is evaluated. DO UNTIL, on the other hand, executes at least once.

10. Is it possible for a variable to be a character data type if it only includes numbers?

Yes, it is dependent on how the variable is use. We’ll wish to use some numbers as a categorical value rather than a quantity in some cases. A variable labelled “Foreigner” is an example of this, with the values “0” and “1” signifying not a foreigner and foreigner, respectively. Similarly, a table’s ID can be a number, but it does not necessarily represent any quantity. Another common example is phone numbers.

11. Can a variable be of the numeric data type if it contains letters or special characters?

No, it has to be a character data type.

12. What is the maximum size of a SAS dataset?

The only limit to the number of observations is the computer’s ability to handle and store them. SAS data sets may have up to 32,767 variables before SAS 9.1. The maximum number of variables in a SAS data set is restricted by your computer’s resources in SAS 9.1.

13. In a proc report, what is the difference between the Order and Group variables?

• Rows with the same values are flattened if the variable is use as a group variable.
• The order variable provides a summary report, whereas the group variables produce a list report.

14. What are some methods for defining variables for the summary report (using proc report)?

A summary report’s variables must be designated as group, analysis, across, or compute variables.

15. PROC MEANS vs. PROC Summary: What’s the difference?

Firstly, PROC MEANS generates a report by default, the difference between the two methods. In PROC SUMMARY, on the other hand, you must include a PRINT option in the PROC SUMMARY statement to generate a report.

16. What does the CROSSLIST option in the TABLES query mean?

When the CROSSLIST option is added to the TABLES statement, crosstabulation tables are displayed in ODS column format.

17. In SAS, what is interleaving?

Interleaving is the process of combining multiple sorted SAS data sets into a single sorted SAS data set. The variable’s value by which the data sets are sorted is shown in the following figure for each observation. A SET combined with a BY statement is use to interleave data sets.

18. What’s the difference between Match Merge and One to One Merge?

A one-to-one merge is appropriate if both data sets in the merge statement are sorted by id (as shown below) and each observation in one data set has a corresponding observation in the other data set.

19. What exactly is PDV?

PDV, or Program Data Vector, represents the logical area in memory. SAS produces a database of one observation at a time at the moment. During compilation, an input buffer is construct to retain a record from an external file. Following the establishment of the input buffer, the PDV is constructed.

20. What data types are SAS capable of handling?

SAS has two data types: numeric and character.

21. In comparison, which statement does not conduct automatic conversions?

The “where” statement in SAS does not do automatic comparison conversions.

22. How do you distinguish between nodupkey and nodup options?

NODUP and NODUPKEY vary in that NODUP compare all of the variables in our dataset, whereas NODUPKEY only compares the BY variables.

23. What is the purpose of the Proc summary function?

The syntax of proc summary and proc means is the same. It generates descriptive statistics for the SAS dataset’s numeric variables.

24. What is the purpose of Proc glm?

Simple and multiple regression, analysis of variance (ANOVAL), analysis of covariance, multivariate analysis of variance, and repeated measure analysis of variance are all performed by Proc glm.

25. What does SAS informats stand for?

SAS INFORMATS are use to read or write data from external files such as ASCII files, text files, and sequential files. SAS will be shown how to read data into SAS variables using the informal.

26. What is the purpose of the CATX syntax?

Concatenates character strings, removes trailing and leading blanks, and inserts separators using the CATX syntax.

27. What is PROC gplot’s purpose in Base Programming Using SAS 9.4?

PROC gplot provides more options and can generate graphics that are more colourful and fancy.

28. What is SAS PROC stand for in Base Programming Using SAS 9.4?

PROC steps are SAS procedures for analysing and processing data in the form of a SAS data set. It manages a collection of routines that perform activities like sorting, summarising, and listing SAS data sets.

29. What is factor analysis, and how does it work in Base Programming Using SAS 9.4?

Factor analysis is a term that refers to a group of statistical techniques for reducing a large number of observable variables to a small number of latent components. Data reduction and summary are the primary goals of factor analysis.

30. How do you check for faults and validate data using SAS Base Programming Using SAS 9.4?

Use the Log to check for problems, and Proc Freq, Proc Means, and sometimes Proc print to view how data looks for data validation.