Presentation on Descriptive Research

1. Descriptive Research-Survey
Compiled by: Dr. V. Singh
What is a Survey ?
A Survey collects information
Is a Census from all the population
Is a Poll if for political information
Is a Sample Survey if from just a sample of a population
INTRODUCTION
• Survey Research Methods are research procedures for collecting large amounts of raw data using
questionnaires.
• It is an effective tool for conducting marketing research.
A field of applied statistics, survey methodology studies the sampling of individual units from a population and the
associated survey data collection techniques, such as questionnaire construction and methods for improving the
number and accuracy of responses to surveys.
Statistical surveys are undertaken with a view towards making statistical inferences about the population being
studied, and this depends strongly on the survey questions used. Polls about public opinion, public health surveys,
market research surveys, government surveys and censuses are all examples of quantitative research that use
contemporary survey methodology to answer questions about a population. Although censuses do not include a
"sample", they do include other aspects of survey methodology, like questionnaires, interviewers, and non response
follow-up techniques. Surveys provide important information for all kinds of public information and research fields,
e.g., marketing research, psychology, health professionals and sociology.
A single survey is made of at least a sample (or full population in the case of a census), a method of data collection (e.g., a
questionnaire) and individual questions or items that become data that can be analyzed statistically. A single survey may
focus on different types of topics such as preferences (e.g., for a presidential candidate), opinions (e.g., should abortion be
legal?), behavior (smoking and alcohol use), or factual information (e.g., income), depending on its purpose. Since survey
research is almost always based on a sample of the population, the success of the research is dependent on the
representativeness of the sample with respect to a target population of interest to the researcher. That target population can
range from the general population of a given country to specific groups of people within that country, to a membership list of
a professional organization, or list of students enrolled in a school system (see also sampling (statistics) and survey
sampling).
Survey methodology as a scientific field seeks to identify principles about the sample design, data collection instruments,
statistical adjustment of data, and data processing, and final data analysis that can create systematic and random survey
errors. Survey errors are sometimes analyzed in connection with survey cost. Cost constraints are sometimes framed as
improving quality within cost constraints, or alternatively, reducing costs for a fixed level of quality. Survey methodology is
both a scientific field and a profession, meaning that some professionals in the field focus on survey errors empirically and
others design surveys to reduce them. For survey designers, the task involves making a large set of decisions about
thousands of individual features of a survey in order to improve it.
Cross-sectional and longitudinal surveys
There is a distinction between one-time (cross-sectional) surveys, which involve a single questionnaire or interview
administered to each sample member, and surveys which repeatedly collect information from the same people over time.
The latter are known as longitudinal surveys. Longitudinal surveys have considerable analytical advantages but they are
also challenging to implement successfully.
Consequently, specialist methods have been developed to select longitudinal samples, to collect data repeatedly, to keep
track of sample members over time, to keep respondents motivated to participate, and to process and analyse longitudinal
survey data
Conditions for a Survey
• Answer the Objectives
• Be Unbiased, Accurate
• Be Generalizable
• Be Ethical
• Be Economical
Before a Survey
• Define the Questions to be answer.
• Define the Sampling strategy.
• Design and Test the Questionnaire.
• Train the field workers.
• Define the technique for cross validation.

2. • Define the final Analysis.
During the Survey
- Verify and cross validate the Questionnaire
- Check Time table and Budget
After the Survey
- Crosscheck again all the data
- Perform the main analysis
- Perform any exploratory data analysis.
The Question
The first task is to clearly and concisely define the Main Question of interest as well as the Target Population of
the study.
Define the Precision or Tolerated error of the estimates: 1% , 5%.
Are there any Nuisance factor to be accounted for, which ones are important?
Stratification
• Sample size proportional to strata size
• Equal sample sizes from all strata
• Sample size inversely proportional to strata variability.
Multiple Steps Sampling
Big Units
2nd Units
Sampling
Units
Questionnaire
• Short and Concise
• Open Questions
• Multiple choice
• Yes/No
Internal Validity
How to check if the subject answers truthfully?
- Ask the same question twice?
Marital status
Spouse age
- Check frequency versus known data
External validity
Are the appropriate questions asked?
Are the questions understandable by all the subjects in the sample.
TYPES OF SURVEY METHODS
• 1.PERSON ADMINISTERD SURVEYS
• 2.TELEPHONE ADMINISTERED SURVEYS
• 3.SELF-ADMINISTERED SURVEYS
• 4.ONLINE SURVEYS

3. 1. PERSON ADMINISTERED SURVEYS
PERSON
ADMINISTERED
INTERVIEW
IN HOME
INTERVIEW
EXCECUTIVE
INTERVIEW
MALL
INTERCEPT
INTERVIEW
PURCHASE
INTERCEPT
INTERVIEW
2.TELEPHONE ADMINISTERED
INTERVIEW
TELEPHONE
ADMINISTERED
INTERVIEW
TELEPHONE
INTERVIEW
COMPUTER
ASSISTED
INTERVIEW
COMPLETELY
AUTOMATED
TELEPHONE SURVEYS
WIRELESS
PHONE
SURVEY
3.SELF-ADMINISTERD
SURVEYS
MAIL
PANEL
SURVEY
DROP
OFF
SURVEY
MAIL
SURVEY
4.ONLINE SURVEY
FAX
SURVEY
INTERNET
SURVEY
E-MAIL
SURVEY
Study of Trends
Cohort
Panel
same same
same
same
new
new
During the Survey
• Collect questionnaires daily.
• Check yesterday questionnaires for missing or
invalid answers.
• Re-interview invalid questionnaires
The Report
• List of Objectives.
• Objectives achieved.
• Sample size estimated.
• Response rate in the sample.
• Main Statistical Analysis.
• Results with significance or Confidence
Interval of estimators.
• Statistical Power of the tests performed.
• Results of the Exploratory Data Analysis
Conclusion
 There are various survey methods used for the purpose of conducting research. These should be convenient
for both the interviewer as well as the respondents, to get the best result.
 The factors should be properly evaluated while selecting an appropriate survey method.
 There are various kinds of errors such as sampling, non-sampling, respondent errors etc & these should be
properly dealt with for effective results.