Post on 18-Dec-2015
Surveys
Dr Carol TaylorCPD and Post-Graduate Studies DivisionSchool of Health, Psychology and Social
CareManchester Metropolitan University
November 2007
Introduction… What are surveys and what are they
not? How is survey data collected? What kinds of data do they generate? How do we analyse it? Why do we use them? What kinds of information do they
provide?
What is a survey? Dictionary definition:
‘Survey’ – view or examination of land or population to examine its features.
Who or what may be surveyed?
Population may be human or non-human trees, animals, Buildings documents, records
Human surveys…
Whole populations National Census
Subgroups… for example:
Children Unemployed Users of a particular product or service Groups of professionals Particular ethnic groups Working mothers
What kind of information do surveys provide?
Descriptive Comparative Explanatory
For knowledge, attitudes and opinions, or behaviour
Studies themselves may be either descriptive or experimental
Demographics Factual personal information about the
individual
For example: questions asking for age, gender, ethnicity, postcode, job title, etc
Behaviours
Self –reports of behaviours Smoking habits Spending habits Leisure pursuits
May be observable, may or may not be “accurate”
Often asked for a scale of frequency of behaviour E.g Frequently, sometimes, rarely, never
Attitudes, beliefs, perceptions
Use of attitude scales E.g: “Strongly agree, partially agree, no view, partially
disagree, strongly disagree”
May be asked to rank list of attitude statements
Use of ‘open – ended’ questions “Why do you feel that way?” “In your view, how might the service be improved”?
Types of studies…
Descriptive studies –
Cross-sectional
Cohort
Case control
Types of studies… Experimental – testing hypotheses
Examine associations
e.g. between lifestyle and health; education and achievement
Examine change - before and after an intervention
e.g. attitudes to back pain after attending a back rehab programme
What are they for? Primarily for information gathering:
Planning (town, workforce, energy)
Examining behaviours (spending, lifestyle)
Attitudes, beliefs, perceptions, opinions (opinion poles, satisfaction surveys)
Screening (Sampling, Identifying a niche market)
Who carries out surveys?For example:Local and National Authorities
TV networks
Commercial companies
Service providers: e.g. - transport authorities, health professionals, educators
What surveys don’t do… Give precise objective measurements.
Establish causal relationships between variables, though may suggest links.
Provide rich qualitative data
Where do surveys sit in the world of research methods?
Research paradigms
Qualitative research e.g. ethnography
Quantitative research e.g. Double blind RCTs
X
Surveys
How is the information (data) collected?
Questionnaire
Interviews Examination Observation
Postal
Telephone
Internet
How is the information (data) collected?
Interviews
Examination – eg documents
Observation - behaviour
individual
focus groups
Face to face
Telephone
What can we do with the data?
Survey data is quantitative.
Descriptive statistics – univariate analysis
Inferential statistics – bivariate / multivariate analysis - Suggest relationships in the data
Statistical significance – e.g. Chi square test
Its data is descriptive but may be examined for differences which have statistical significance.
What next…?
Data generation….
…and analysis
Sampling? Representative sample
Purposive sample
Sample size
Types of questions Closed ended
Factual data Fixed choice Likert scales
Open ended
Closed-ended: Factual data….
Demographics
e.g. Age, occupation, type of dwelling, income
Contributes to examining populations’ living and working habits for example.
Fixed choice…Which of the following newspapers do you
read?:The TimesThe DailyTelegraphThe IndependentThe Daily MailThe SunManchester Evening NewsOtherIf other, please state………………………………..
Likert Scales The doctor listened to you attentively
Strongly disagree Partially disagreeNeither agree nor disagreePartially agreeStrongly agree
How often do you question the doctor’s advice?NeverRarelySometimesFrequentlyAlways
Types of questions Closed ended
Factual data Fixed choice Likert scales
Open ended No predetermined choices or responses Usually asking for opinions, beliefs, attitudes etc. Respondent free to provide their own responses to
the question. This does not include “any other comments?”
Open ended questions…
What are your views on the Government’s ban on smoking in pubs?
Response rates Relevance
Timeliness
Convenience
Analysing the data Closed ended questions
Open ended questions
Closed - ended questions
Levels of measurement Nominal Ordinal Interval (Ratio)
Most commonly nominal and ordinal data
Analysing the dataNominal data Univariate analysis - the proportion of
responses in each category Methods: charts (e.g. bar chart, pie chart) or frequency table.
Presented as descriptive statistics.
May use multiway tables and tests of statistical significance (e.g.Chi Square) to measure associations between variables
Analysing the data
Multiway tables influenced by: The number of variables being examined
Bivariate = 2 variables (e.g. gender + purchase of computers) Methods: cross-tabulations (2 x 2 tables) scatterplots; regression; comparison of means
Support for going into Iraq?
% Strongly approve 159 3.8 Approve 125030.1 33.9 positive
Disapprove 141133.9 Strongly disapprove 124429.9 63.8negative
DK 93 2.2 Total 4157100 (99.9)
Is there a gender effect? approve disapprove
total Men 765 (42%)1045 (58%) 100%
1810 Women 642 (29%)1608 (71%)
100% 2250
13 -13
Analysing the data Multivariate = 3 or more variables
e.g. income influenced by both education level and gender.
Therefore assuming we have a representative sample to begin with, we can infer something about the population as a whole.
Analysing the data Ordinal data e.g.Likert Scales
Tend to convert responses to numerical codes e.g. Completely disagree = 1; Completely agree = 5
These are codes only but some order can be assumed.
Modes and central tendencies may be useful but means are not.
Data analysis
0
5
10
15
20
25
30
35
40
S/ D D N A S/ A
Qu1Qu2Qu3
Responses to 3 five-point Likert scale questions
Open ended questions
Qualitative information which is examined for themes.
Usually do content analysis presenting themes as frequency tables.
What kind of data do we get?
Data is presented numerically from both open and closed questions.
Questionnaires are therefore quantitative in nature even though they may ask for qualitative information.
Ethical considerations Survey participants deserve all the
same rights as participants in other types of study. Research governance applies!
Ethical approval from a REC not necessary unless the participants are NHS patients and /or from a recognised vulnerable group
Advantages of questionnaires
Access to large numbers in wide geographical area
Relatively easy / quick to analyse
Large volume of descriptive information
Relatively cheap to administer
Disadvantages of questionnaires Difficult to construct well
Information may lack depth
Information may not be accurate (memory, perceptions etc)
Commonly poor response rates
Delphi technique Uses questionnaires to gain a consensus on
a particular issue
Useful where there is little or no convincing research evidence on a specific topic
Barker K and Burns M (2001) Using consensus techniques to produce clinical guidelines for patients treated with the Ilizarov fixator. Physiotherapy Vol 87 No 6 pp 289-297
Key Points…. Surveys examine characteristics of
populations Surveys are a quantitative method
of research Results are not precise objective
measures but can suggest links between variables