Data Dr Poonam R Naik Professor Community Medicine

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Data Dr Poonam R Naik Professor Community Medicine Yenepoya Medical College

Data Dr Poonam R Naik Professor Community Medicine Yenepoya Medical College

Introduction Ø Statistics: Data and statistical methods Ø Statistics: Management of numerical data derived

Introduction Ø Statistics: Data and statistical methods Ø Statistics: Management of numerical data derived from a group of individuals Ø Biostatistics: sciences Branch applied to medical

Ø Variable: A characteristic which takes on different values in different persons, places or

Ø Variable: A characteristic which takes on different values in different persons, places or things. Example: Height, weight, blood pressure. Ø Data: A set of values recorded on one or more observational units. They are raw material of statistics.

Types of data i. Qualitative & Quantitative ii. Discrete & Continuous iii. Grouped &

Types of data i. Qualitative & Quantitative ii. Discrete & Continuous iii. Grouped & Ungrouped iv. Primary & Secondary v. Nominal & Ordinal

Characteristics of data? ? ?

Characteristics of data? ? ?

Characteristics of data i. Accurate: It measures true value of what is under study

Characteristics of data i. Accurate: It measures true value of what is under study ii. Valid: It measures only what it is supposed to measure iii. Precise: Variable has the same value when measured several times iv. Reliable: It should be dependable

Data collection �What is your research question? �What is primary objective of your study?

Data collection �What is your research question? �What is primary objective of your study? �Who are your subjects? �What type of data is required? �Give examples: Individual Activity

Types of data collection Primary ii. Secondary i.

Types of data collection Primary ii. Secondary i.

Primary Data �Data collected for basic research question with different tools �Used for: i.

Primary Data �Data collected for basic research question with different tools �Used for: i. Description of variables ii. Compare with old data iii. Address new area iv. Teaching Learning or research purpose

Data collection strategies i. Experiments and Quasi experiments ii. Surveys using structured questionnaires iii.

Data collection strategies i. Experiments and Quasi experiments ii. Surveys using structured questionnaires iii. Qualitative research

Primary Data Collection Experiments: Ø Researcher conducts experiment on a defined number of participants

Primary Data Collection Experiments: Ø Researcher conducts experiment on a defined number of participants with a specific research question Ø Having a planned study design Ø Has predictor and outcome variables 1.

II. Social Survey: Ø Interview survey Ø Large and representative sample Ø Questionnaire has

II. Social Survey: Ø Interview survey Ø Large and representative sample Ø Questionnaire has a set of questions: Open ended, Close ended Ø Information about: behaviour, attitude, KAP studies, prevalence studies Ø Population could be households or specific groups Ø Careful designing of questions is essential: Pilot study

III. Qualitative research: To know in depth about perceptions, causes, behaviour…. i. In depth

III. Qualitative research: To know in depth about perceptions, causes, behaviour…. i. In depth interview ii. Focus group discussions iii. Mapping iv. Observe events v. Moderator, rapporteur, Sociogram vi. AV recording vii. Information saturation

Advantages of primary data: i. Original and relevant to the topic : Degree of

Advantages of primary data: i. Original and relevant to the topic : Degree of accuracy is very high. ii. It can be collected by interviews, telephone surveys, focus groups etc. iii. It can be also collected across the national borders. iv. Includes a large population and wide geographical coverage. v. Reliability of primary data is very high

Disadvantages of primary data: i. Wider coverage: More number of researchers are required. ii.

Disadvantages of primary data: i. Wider coverage: More number of researchers are required. ii. Time and effort required for data collection. iii. Survey design iv. The questions must be simple to understand respond. v. Responses may be doubtful. vi. Higher cost vii. Incomplete questionnaire: Negative impact on research. viii. Trained persons required for data collection.

Secondary Data �Of existing data �Official statistics,

Secondary Data �Of existing data �Official statistics,

Challenges: Locate the source of existing data It must be useful Available to the

Challenges: Locate the source of existing data It must be useful Available to the researcher Detailed description of the data including methodology Ability to use the data effectively due to vast information

Evaluation of secondary data Ø Research question driven Ø Steps to evaluate: i. Study

Evaluation of secondary data Ø Research question driven Ø Steps to evaluate: i. Study purpose ii. Data collection details, Sampling method iii. Variables studied

Advantages of secondary data are following: • Cheaper and faster to access. • A

Advantages of secondary data are following: • Cheaper and faster to access. • A way to access the work of the best scholars all over the world. • Saves time, efforts and money and add to the value of the research study.

Disadvantages of secondary data • Reliability and accuracy of data? ? ? • Data

Disadvantages of secondary data • Reliability and accuracy of data? ? ? • Data collected in one location may not be suitable for the other one With the passage of time the data becomes obsolete and very old • Secondary data collected can distort the results of the research. • Secondary data can also raise issues of authenticity and copyright.