LECTURE 3 TYPES OF DATA AND METHODS OF

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LECTURE 3 TYPES OF DATA AND METHODS OF DATA COLLECTION Types of data and

LECTURE 3 TYPES OF DATA AND METHODS OF DATA COLLECTION Types of data and methods of data collecton PRESENTED BY: MRS. IRAM WAQAR 3/1/2021 1

WHAT IS DATA? • The word data is used for numerical facts and a

WHAT IS DATA? • The word data is used for numerical facts and a single numerical fact is datum. • A set of values recorded on one or more observational units. • Data are the facts and figures collected, summarized, analyzed, and interpreted. • The term data refers to any kind of information researchers obtain on the subjects, respondents or participants of the study. In research, data are collected and used to answer the research questions or objectives of the study. Types of data and methods of data collecton 3/1/2021 2

TYPES OF DATA Data Numerical Quantitative Categorical Qualitative Discrete Nominal Continuous Ordinal Interval Types

TYPES OF DATA Data Numerical Quantitative Categorical Qualitative Discrete Nominal Continuous Ordinal Interval Types of data and methods of data collecton Ratio 3/1/2021 3

Qualitative / Categorical Population is classified into various categories and data is recorded in

Qualitative / Categorical Population is classified into various categories and data is recorded in the form of “counts”, this is called qualitative data / variables. For example gender (male, female), eye color, hair color, complexion of skin etc. • These variables are measured as discrete / discontinuous numbers (no decimal places, and cannot be divided into fractions). For example number of rats in an experiment. Types of data and methods of data collecton 3/1/2021 4

Quantitative / Numerical When we make observations numerically and the variable to be measured

Quantitative / Numerical When we make observations numerically and the variable to be measured is numerical value then this is called quantitative data / variable. For example blood glucose level, weight, height etc. • These variables are measured as continuous numbers that is capable of taking every possible value between two given numbers is termed as continuous. For example, age, weight (52. 5 kg). Types of data and methods of data collecton 3/1/2021 5

 • Based on their mathematical properties, data are divided into FOUR groups: NOIR

• Based on their mathematical properties, data are divided into FOUR groups: NOIR 1. Nominal 2. Ordinal 3. Interval 4. Ratio Types of data and methods of data collecton 3/1/2021 6

1. NOMINAL DATA • The most elementary scale • Just identify categories; species, gender,

1. NOMINAL DATA • The most elementary scale • Just identify categories; species, gender, color • No difference could be made by arrangements • Examples are gender – female and male; eye color – black, brown, green • For qualitative / categorical variables Types of data and methods of data collecton 3/1/2021 7

2. ORDINAL DATA • Have all the properties of “nominal scale”; classifying and labeling,

2. ORDINAL DATA • Have all the properties of “nominal scale”; classifying and labeling, for example • New thing is “a sense of order / arrangements” • Ordinal numbers / data are used to “rank order” • For example, DAFOR • • Category Score • Dominant 5 • Abundant 4 • Frequent 3 • Occasional 2 • Rare 1 • There is no relationship between numerical values of abundance scale, i. e. Abundant does not mean twice Occasional Types of data and methods of data collecton 3/1/2021 8

3. INTERVAL DATA • In addition to classification and ranking, interval scale allows the

3. INTERVAL DATA • In addition to classification and ranking, interval scale allows the recognition of precisely “how far apart are the individual classes from each other on the scale” For example: The distance between 8 th and 9 th points on the scale is the same as that between the 3 rd and 4 th • Date is a very widely used interval scale variable • There is no absolute zero, so, it is not possible to say that 9 th value is 3 times that of 3 rd Types of data and methods of data collecton 3/1/2021 9

4. Ratio DATA • The highest level of measurement • Incorporates the properties of

4. Ratio DATA • The highest level of measurement • Incorporates the properties of nominal, ordinal and interval scales • Includes an absolute zero, in addition • All mathematical procedures of +, -, x and / are possible • Examples are length and mass; for example, length of 150 mm is three times as long as 50 mm • Height, Weight, age etc. Types of data and methods of data collecton 3/1/2021 10

METHODS OF DATA COLLECTION Types of data and methods of data collecton 3/1/2021 11

METHODS OF DATA COLLECTION Types of data and methods of data collecton 3/1/2021 11

 • Statistics is a tool for converting data into information: Statistics Data Information

• Statistics is a tool for converting data into information: Statistics Data Information But where then does data come from? How is it gathered? How do we ensure its accurate? Is the data reliable? Is it representative of the population from which it was drawn? Types of data and methods of data collecton 3/1/2021 5. 12

Key Concepts • A population is the collection of all items or things under

Key Concepts • A population is the collection of all items or things under consideration o A parameter is a summary measure that describes a characteristic of the entire population • A sample is a portion of the population selected for analysis o A statistic is a summary measure computed from a sample to describe a characteristic of the population Types of data and methods of data collecton 3/1/2021 13

Key Concepts, Continued • Descriptive statistics ---- Collecting, summarizing, and describing (presenting) data from

Key Concepts, Continued • Descriptive statistics ---- Collecting, summarizing, and describing (presenting) data from a sample or a population • Inferential statistics – The process of using sample statistics to draw conclusion about the population parameters Types of data and methods of data collecton 3/1/2021 14

Example: Descriptive Statistics • Collect data o e. g. , Survey • Present data

Example: Descriptive Statistics • Collect data o e. g. , Survey • Present data o e. g. , Tables and graphs • Characterize data o e. g. , Sample mean = Types of data and methods of data collecton 3/1/2021 15

Example: Inferential Statistics • Estimation o e. g. , Estimate the population mean weight

Example: Inferential Statistics • Estimation o e. g. , Estimate the population mean weight using the sample mean weight • Hypothesis testing Types of data and methods of data collecton 3/1/2021 16

Sources of data • Before collection of data , a decision maker needs to:

Sources of data • Before collection of data , a decision maker needs to: o Prepare a clear and concise statement of purpose o Develop a set of meaningful measurable specific objective o Determine the type of analyses needed o Determine what data is required Types of data and methods of data collecton 3/1/2021 17

Sources of Data, Continued • Primary Data: These are information collected directly from the

Sources of Data, Continued • Primary Data: These are information collected directly from the subjects being studied, such are people, areas, or object. • Primary Data Collection Methods o Experimental Design o Conduct Survey o Observation (focus group) • Secondary Data Compilation/Collection o Mostly governmental or industrial, but also individual sources. Types of data and methods of data collecton 3/1/2021 18

Types of Data • Random Variable – Values obtained are not controlled by the

Types of Data • Random Variable – Values obtained are not controlled by the researcher (theoretically values differ from item to item) • Data from a RV are either: o Quantitative • Continuous (measuring) • Discrete (Counting) o Qualitative (categorical) • Nominal • Ordinal Types of data and methods of data collecton 3/1/2021 19

Types of Sampling Methods • • Non-Probability Sampling -- Items included are chosen without

Types of Sampling Methods • • Non-Probability Sampling -- Items included are chosen without regard to their probability of occurrence. i. Judgment ii. Quota iii. Chunk iv. Convenience Probability Sampling – Items are chosen based on a known probability. Let N=size of the population and n=desired sample size i. With replacement ii. Without replacement Types of data and methods of data collecton 3/1/2021 20

Types of Probability Sampling • Items in the sample are chosen based on known

Types of Probability Sampling • Items in the sample are chosen based on known probabilities Probability Samples Simple Random Systematic Types of data and methods of data collecton Stratified Cluster 3/1/2021 21

Types of Probability Samples, Con’t • Simple Random Sample -- Every individual or item

Types of Probability Samples, Con’t • Simple Random Sample -- Every individual or item from the frame has an equal chance of being selected. In addition, any selected sample has the same chance of being selected as any other. o Samples obtained from table of random numbers or computer random number generators • Systematic Samples -- A systematic sample is a sample in which each member of the population is assigned a number. The members of the population are ordered in some way, a starting number is randomly selected, and then sample members are selected at regular intervals from the starting numbers. For example , every 3 rd or 5 th one is selected. An advantage of this is that it is easy to use. Types of data and methods of data collecton 3/1/2021 22

Types of Probability Samples, Con’t • Stratified samples -- Divide population into subgroups (called

Types of Probability Samples, Con’t • Stratified samples -- Divide population into subgroups (called strata) according to some common characteristic such as age, gender, ethnicity or even political preference. • A simple random sample is selected from each subgroup. Samples from subgroups are combined into one. • Cluster Samples -- Population is divided into several “clusters, ” each representative of the population. Then, a simple random sample of clusters is selected • To select a cluster sample, divide the population into groups called clusters, and select all the members in one or more(but not all) of the clusters. • Examples of clusters could be different sections of the same course. Mrs. Bode’s 1 st period Statistics class and her 3 rd period Statistics class. Types of data and methods of data collecton 3/1/2021 23

Sampling and Non-Sampling Errors… • Two major types of error can arise when a

Sampling and Non-Sampling Errors… • Two major types of error can arise when a sample of observations is taken from a population: • Sampling error refers to differences between the sample and the population that exist only because of the observations that happened to be selected for the sample. Random and we have no control over. • Non-sampling errors are more serious and are due to mistakes made in the acquisition of data or due to the sample observations being selected improperly. Most likely caused be poor planning, sloppy work, act of the Goddess of Statistics, etc. Types of data and methods of data collecton 3/1/2021 5. 24

Sampling Error… • Sampling error refers to differences between the sample and the population

Sampling Error… • Sampling error refers to differences between the sample and the population that exist only because of the observations that happened to be selected for the sample. • Increasing the sample size will reduce this type of error. Types of data and methods of data collecton 3/1/2021 5. 25

Non-sampling Error… • Non-sampling errors are more serious and are due to mistakes made

Non-sampling Error… • Non-sampling errors are more serious and are due to mistakes made in the acquisition of data or due to the sample observations being selected improperly. Three types of nonsampling errors: • Errors in data acquisition, • Nonresponse errors, and • Selection bias. • Note: increasing the sample size will not reduce this type of error. Types of data and methods of data collecton 3/1/2021 5. 26

Errors in data acquisition… • …arises from the recording of incorrect responses, due to:

Errors in data acquisition… • …arises from the recording of incorrect responses, due to: • — incorrect measurements being taken because of faulty equipment, • — mistakes made during transcription from primary sources, • — inaccurate recording of data due to misinterpretation of terms, or • — inaccurate responses to questions concerning sensitive issues. Types of data and methods of data collecton 3/1/2021 5. 27

Non-response Error… • …refers to error (or bias) introduced when responses are not obtained

Non-response Error… • …refers to error (or bias) introduced when responses are not obtained from some members of the sample, i. e. the sample observations that are collected may not be representative of the target population. • Response Rate (i. e. the proportion of all people selected who complete the survey) is a key survey parameter and helps in the understanding in the validity of the survey and sources of nonresponse error. Types of data and methods of data collecton 3/1/2021 5. 28

Selection Bias… • …occurs when the sampling plan is such that some members of

Selection Bias… • …occurs when the sampling plan is such that some members of the target population cannot possibly be selected for inclusion in the sample. Types of data and methods of data collecton 3/1/2021 5. 29

Methods of Collecting Data… • There are many methods used to collect or obtain

Methods of Collecting Data… • There are many methods used to collect or obtain data for statistical analysis. Three of the most popular methods are: • Observation • Experiments, and • Surveys. Types of data and methods of data collecton 3/1/2021 5. 30

Observation Method Observation method is a method under which data from the field is

Observation Method Observation method is a method under which data from the field is collected with the help of observation by the observer or by personally going to the field. • In the words of P. V. Young, “Observation may be defined as systematic viewing, coupled with consideration of seen phenomenon. ” ADVANTAGES • Subjective bias eliminated (No bias info) • Information researcher gets is Current information • Independent to respondent’s variable (as in interview and may be bias) DISADVANTAGES : • It is expensive method (time requires more) • Limited information • Unforeseen factors may interfere with observational task • Respondents opinion can not be recorded on certain subject Types of data and methods of data collecton 3/1/2021 31

TYPES OF OBSERVATION Structured and Unstructured Observation • When observation is done by characterizing

TYPES OF OBSERVATION Structured and Unstructured Observation • When observation is done by characterizing style of recording the observed information, standardized conditions of observation, selection of pertinent data of observation then it is structured observation • When observation is done without any thought before observation then it is unstructured observation Types of data and methods of data collecton 3/1/2021 32

Participant & Non Participant Observation • When the Observer is member of the group

Participant & Non Participant Observation • When the Observer is member of the group which is observing then it is Participant Observation • In participant observation researcher can record natural behavior of group. Non Participant Observation • When observer is observing people without giving any information to them then it is non participant observation Types of data and methods of data collecton 3/1/2021 33

Controlled & Uncontrolled Observation • When the observation takes place in natural condition i.

Controlled & Uncontrolled Observation • When the observation takes place in natural condition i. e. uncontrolled observation. It is done to get spontaneous picture of life and persons • When observation takes place according to definite pre arranged plans with experimental procedure then it is controlled observation generally done in laboratory under controlled condition. Types of data and methods of data collecton 3/1/2021 34

Experiment Method • In a experiment the experimenter applies 'treatments' to groups of subjects.

Experiment Method • In a experiment the experimenter applies 'treatments' to groups of subjects. For example the experimenter may give one drug to group 1 and a different drug to group 2, to determine the effectiveness of the drug. • An experiment is a method that most clearly shows cause-and-effect because it isolates and manipulates a single variable, in order to clearly show its effect. • Experiments almost always have two distinct variables: First, an independent variable (IV) is manipulated by an experimenter. • Then the experimenter measures the second variable, the dependent variable (DV). Types of data and methods of data collecton 3/1/2021 35

Characteristics of a true Experiment 1. Sample equivalent experimental and control groups 2. Isolate

Characteristics of a true Experiment 1. Sample equivalent experimental and control groups 2. Isolate and control the treatment 3. Measure the effect Types of data and methods of data collecton 3/1/2021 36

Pre-test/Post-test with Control R MB 1 X MA 1 Experimental group R MB 2

Pre-test/Post-test with Control R MB 1 X MA 1 Experimental group R MB 2 MA 2 Control group R denotes random assignment to groups X denotes the treatment Expmt gp - Measure of effect = Types of data and methods of data collecton Control gp = (MA 1 -MB 1) - (MA 2 -MB 2) = with vs without 3/1/2021 37

Research Designs/Data Collection Approaches 3/1/2021 Types of data and methods of data collecton 38

Research Designs/Data Collection Approaches 3/1/2021 Types of data and methods of data collecton 38

Qualitative vs Quantitative Approaches Qualitative In-Depth Interview Case Study Participant observation Secondary data analysis

Qualitative vs Quantitative Approaches Qualitative In-Depth Interview Case Study Participant observation Secondary data analysis Quantitative Surveys Experiments Structured observation Secondary data analysis Types of data and methods of data collecton 3/1/2021 39

Surveys • A survey is an investigation about the characteristics of a given population

Surveys • A survey is an investigation about the characteristics of a given population by means of collecting data from a sample of that population and estimating their characteristics through the systematic use of statistical methodology. • The Response Rate (i. e. the proportion of all people selected who complete the survey) is a key survey parameter. • • Surveys may be administered in a variety of ways, e. g. Personal Interview Telephone Interview Self Administered Questionnaire Types of data and methods of data collecton 3/1/2021 5. 40

Personal Interview • The interviewer asks questions generally in a face to face contact

Personal Interview • The interviewer asks questions generally in a face to face contact to the other person or persons. • The interviewer can observe the body language of the respondent. • The interviewer can probe for clarification of ambiguous responses. Interview is effective for semi- literate or illiterate respondents. The expected response rate in an interview is high. • Advantages o Can clarify doubts about questionnaire o Relatively high response/cooperation o Special visual aids and scoring devises can be used • Disadvantages o o o High costs and time intensive Geographical limitations Response bias / Confidentiality difficult to be assured Some respondents are unwilling to talk to strangers Trained interviewers Types of data and methods of data collecton 3/1/2021 41

Telephone Interview • Advantages o Discomfort of face to face is avoided o Faster

Telephone Interview • Advantages o Discomfort of face to face is avoided o Faster / Number of calls per day could be high o Lower cost • Disadvantages o Interview length must be limited o Low response rate o No facial expressions © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 42

Self-administered • In this Questionnaires are given to the respondents who are asked to

Self-administered • In this Questionnaires are given to the respondents who are asked to read answer the questions themselves. • Questions and instructions are addressed to the respondents. • Instructions on how to accomplish the questionnaire are clearly specified in the instrument. • Advantages o o Lowest cost option Expanded geographical coverage Requires minimal staff External influence is avoided. Respondents have time to think before answering because they are not under pressure to give an answer immediately. • Disadvantages o o Low response rate in some modes No interviewer intervention possible for clarification Cannot be too long or complex Incomplete surveys Types of data and methods of data collecton 3/1/2021 43

Principles of Questionnaire Design. © 2009 John Wiley & Sons Ltd. Types of data

Principles of Questionnaire Design. © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 44

Questionnaire Design • Definition A questionnaire is a pre-formulated, written set of questions to

Questionnaire Design • Definition A questionnaire is a pre-formulated, written set of questions to which the respondent records his answers • Steps 1. 2. 3. 4. 5. Determine the content of the questionnaire Determine the form of response Determine the wording of the questions Determine the question sequence Write cover letter © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 45

1. Questionnaire content • Framework Need information for all constructs in framework • Measurement:

1. Questionnaire content • Framework Need information for all constructs in framework • Measurement: Operationalizing o Objective construct: o Subjective construct: © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 46

2. Response format • Open-ended questions are questions that allow someone to give a

2. Response format • Open-ended questions are questions that allow someone to give a free-form answer e. g essay writing. • Closed-ended questions can be answered with “Yes” or “No, ” or they have a limited set of possible answers (such as: A, B, C, or All of the Above). • Closed vs. Open-ended questions o Closed questions • Helps respondents to make quick decisions • Helps researchers to code o Open-ended question • First: unbiased point of view • Final: additional insights • Complementary to closed question: for interpretation purpose © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 47

3. Question Wording • Avoid double-barreled questions • Avoid ambiguous questions and words •

3. Question Wording • Avoid double-barreled questions • Avoid ambiguous questions and words • Use of ordinary words • Avoid leading or biasing questions • Social desirability • Avoid recall depended questions © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 48

4. Question Sequence Personal and sensitive data at the end © 2009 John Wiley

4. Question Sequence Personal and sensitive data at the end © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 49

5. Cover Letter • The cover letter is the introductory page of the questionnaire

5. Cover Letter • The cover letter is the introductory page of the questionnaire • It includes: o Identification of the researcher o Motivation for respondents to fill it in o Confidentiality o Thanking of the respondent © 2009 John Wiley & Sons Ltd. Types of data and methods of data www. wileyeurope. com/college/sekaran collecton 3/1/2021 50

Other Methods of Data Collection üIn-Depth Interview • To discover the underlying motives or

Other Methods of Data Collection üIn-Depth Interview • To discover the underlying motives or desires of samples. To explore needs , feelings of respondents. Skill is required , indirect question or projective techniques are used to know behavior of the respondent. • Content Analysis--- analyzing contents of documentary material as news paper , books , magazines about certain characteristics to identify and count. Types of data and methods of data collecton 3/1/2021 51

üCASE STUDY METHOD • It is essentially an intensive investigation of the particular unit

üCASE STUDY METHOD • It is essentially an intensive investigation of the particular unit under consideration. Its important characteristics are as follows : a) the researcher can take one single social unit b) the selected unit is studied intensively i. e. it is studied in minute details. Types of data and methods of data collecton 3/1/2021 52

THE RESEARCH INSTRUMENT Types of data and methods of data collecton 3/1/2021 53

THE RESEARCH INSTRUMENT Types of data and methods of data collecton 3/1/2021 53

INSTRUMENTATION • There are several kinds of instruments that can be used in data

INSTRUMENTATION • There are several kinds of instruments that can be used in data collection. Certain conditions dictate the type of instrument to use, such as the: • Characteristics of the research subjects/respondents • Availability of subjects/ respondents • Available resources for the study. • Since conclusions of a study are based on what the data reveal, it is important that the instruments used to collect data are valid and reliable Types of data and methods of data collecton 3/1/2021 54

Validity and Reliability of a Research Instrument Validity of an Instrument: Validity refers to

Validity and Reliability of a Research Instrument Validity of an Instrument: Validity refers to the appropriateness and usefulness of inferences a researchers makes on the data they collect. A research instrument is valid when it measures what it intends to measure. Three kinds of Validity of an Instrument ü Content Validity ü Criterion Related Validity ü Construct Related Validity Types of data and methods of data collecton 3/1/2021 55

Content Validity: • An instrument has a content-Validity if the content and format of

Content Validity: • An instrument has a content-Validity if the content and format of an instrument appropriately covers the topics and variables intended to be studied and the items adequately represent the subject to be assessed. • The key element in content validity is the adequacy of sampling of items that are included in the instrument. How to determine Content-Validity • A common way of determining the content validity of an instrument is by having one or more individual look at the content and format of the instrument and judge whether or not they are appropriate. • When two or more individuals evaluate the instrument, the process is called “ Jury Validation ” Types of data and methods of data collecton 3/1/2021 56

Criterion-Related Validity: • An instrument has criterion related Validity if a score obtained by

Criterion-Related Validity: • An instrument has criterion related Validity if a score obtained by an individual using a particular instrument is significantly associated with a score he/she obtains on another instrument or another measure, known as the criterion. How to determine Criterion Related Validity • To determine the criterion-related validity of an instrument, a researcher can compare the answers or responses of the subjects or respondents in the instrument being evaluated with their responses in the another instrument, called the Criterion. • For example: If one wants to measure academic performance of student, he/she can get the student’s general average in all academic subjects and compare this to his college entrance exam score, which can be the Criterion Variable. Types of data and methods of data collecton 3/1/2021 57

Construct –Related Validity: • It refers to specific psychological constructs or characteristics being measured

Construct –Related Validity: • It refers to specific psychological constructs or characteristics being measured by the instrument and how well these constructs explain the differences in the behavior of individuals. How to determine the Construct-related Validity: • Define the variable • Formulate a hypothesis based on theory • Testing the hypothesis both logically and empirically. Types of data and methods of data collecton 3/1/2021 58

Reliability of the Research Instrument: • Reliability refers to the consistency of the response

Reliability of the Research Instrument: • Reliability refers to the consistency of the response or the scores obtained by an individual in a test or research instrument administered twice. • For example in a test I math, a student is expected to get a high grade, in the second administration if his/her score in the first is high. Reliability of this test can also be determined if two forms of the test can be prepared and the scores of the students in the two forms can be compared. Types of data and methods of data collecton 3/1/2021 59

THANKS STAGES OF RESEARCH 3/1/2021 60

THANKS STAGES OF RESEARCH 3/1/2021 60