Unit 5: Research Method, Design, and Sampling; Ethics; Theory, Connaway & Powell Chapter 4

Survey Research and Sampling

Survey: group of research methods used to determine the present status of a given phenomenon
- to make inferences about a large group of elements by studying  relatively small number selected from a larger group

define: to look over/see beyond

• Observations
• Population
• Data
• Bias

Major Differences Survey Types & Other Methods of Research

• Survey gathers contemporary data
• Historical Research concerned with past data

Contrast experimental -

• doesn't enable researcher to manipulate the independent variable
• less control of research environment
• not considered capable of definitely establishing causal relationship
• less rigorous than experimental
• better suited to study large number of cases
• geographically dispersed
• more appropriate personal factors/exploratory analysis of relationships

Types of Survey Studies

Exploratory Surveys

1. Literature surveys
2. Experience surveys
3. Analysis of "insight-stimulating" examples

Analytical and Descriptive Surveys

appropriate for data - quantitative in nature, require statistical assistance to extract meaning
descriptive survey - MOST COMMON TYPE OF SURVEY = (SURVEY RESEARCH METHOD)

• Other Types of Surveys

1. Cross sectional
2. Trend study
3. Cohort study
4. Panel study
5. Approximation of a longitudinal study
6. Parallel samples study
7. Contextual study
8. Socio-metric study
9. Critical incident study

Basic Purposes of Descriptive Surveys - describe characteristics of population of interest, estimate proportions, make specific predictions, test associational relationships

• can consider but not test causal relationships, 
• can test associations relationships
• do tend to 
• could conclude
• seems to be a correlation

other factors or variables

• could influence more
• cannot control so could not test
• relationship must make sense conceptionally regardless of methodology/technique

Basic Steps of Survey Research Overview

• Formulating Objectives
• Selecting Data Collection Techniques
• Selecting the Sample
• Collecting the Data
• Analyzing and Interpreting the Results
• Survey Research Designs
• Survey Research Costs
• shorten length of data collection
• reduce number of follow ups
• limit pilot or pretest to small no. participants
• shorten time spent developing data collection instruments - adapt to existing instruments
• make instrument as short as possible
• use non-monetary incentives to encourage respondents
• minimize staff costs
• shop around for least expensive supplies and equipment
• reduce number of survey activities
• minimize amount of time each activity takes

Sampling - MOST CRUCIAL STEP

Basic Terms and Concepts

• Universe 
• Population
• Population Stratum - subdivision of a population based on specification or characteristic
• Element - individual member
• Census - count of all and determine characteristics
• Sample - selection of units
• Case - individual members (lower case n)
• Sampling Frame - actual list of units from which the sample is selected

Types of Sampling Methods

• Non-probability Sampling
• Accidental Sample
• Quota Sample
• Snowball Sample
• Purposive Sample
• Self-Selected Sample
• Incomplete Sample
• Probability Sampling
• Simple Random Sample SRS
• Selecting the Simple Random Sample
• number sequentially elements in population
• determine how many are to be elected
• select 3 digit numbers from table to give every element a chance of selection
• choose starting point and pattern
• processed in pattern
• select those to skip
• Systematic Sample
• Stratified Random Sample
• Cluster Sample

Combination of Cluster, Stratified and simple random EXAMPLE

• entire 48 continguous state divided into small areas called PRIMARY SAMPLING UNITS (PSU) usually counties, metro areas, tele exchange, A stratified  random sample o 75 are selected from total

• PSU is stratified into large, small and smaller cities and/or rural areas. Each unit is a SAMPLE PLACE

• Sample place divided into CHUNKS/BLOCKS, a number are randomly selected

• Chunks broken down into SEGMENTS, containing 4-12 dwelling units, segments randomly drawn from each chunk

• DWELLING UNITS, constitute final sample. city directory can obtain telephone numbers for those chosen

Determining the Sample Size
general rule of thumb, larger the better, less than 100 not likely to represent population
General Criteria

1. degree of precision required between sample and population, less accuracy=smaller sample
2. variability of the population, greater variability=larger sample
3. method of sampling / stratified sampling requires fewer cases than simple or systematic random
4. way in which the results are to be analyzed / small=significant limitations on types of statistics

Use of Formulas

Sampling Error

Other Causes of Sampling Error

Non-Sampling Error

Sampling in Library Use

Non-Random Sampling

Random Sampling Over Time

Conclusions

Summary