XX 352 - Unit 3_Research Design.pdf

28/06/2024 CE/EL/ES/GL/GM/MA/MC 352 – Research Methods & Ethics in Science DEPARTMENT OF ENVIRONMENTAL AND SAFETY ENGINEERING...

28/06/2024 CE/EL/ES/GL/GM/MA/MC 352 – Research Methods & Ethics in Science DEPARTMENT OF ENVIRONMENTAL AND SAFETY ENGINEERING LECTURER: Kenneth Asamoah Boateng, PhD 1 1 Objectives This course will equip students with skills in conducting scientific research with regard to data collection, analysis, interpretation and report writing. 2 1  28/06/2024 Mode of Delivery Lectures (face-to-face and online using Virtual Learning Environment), tutorials, seminar, group work and assignment. Reading Material Bailey, C. A. (2017), A Guide to Qualitative Field Research, Sage Publications, California, United States, 3rd Edition, 280 pp. D’angelo, J. (2018), Ethics in Science: Ethical Misconduct in Scientific Research, CRC Press, Florida, United States, 160 pp. Mike, W. M. (2008), Creativity: Ethics and Excellence in Science, Lexington Books, Washington DC, United States, 149 pp. Teti, D. M. (2004), Handbook of Research Methods in Developmental Science, Wiley-Blackwell, New Jersey, United States, 1st Edition, 584 pp. 3 Assessment Student assessment will be based on 1. Continuous assessment 30% (Quizzes, assignments, experimental work, etc.) 2. Attendance 10 % 3. EXAMS 60% 4 2  28/06/2024 Contact Information Mobile Number Email Addresses +233267170846 [email protected] WhatsApp +233267170846 5 5 Course Content Research Methods & Ethics in Science Definition and concepts of research. Research process. Research design. Literature review. Sampling. Reliability and validity of data. Qualitative and quantitative research methods. Research reporting. Definition of ethics. Definition of science. 6 6 3  28/06/2024 Course Content Research Methods & Ethics in Science Definition of ethics in science. What is a profession? How ethics and values intersect with professionalism. Ethical theory and applications. Standards of ethical conduct in science. Common ethical principles in science. Fraud in science. Whistle blowing. Conflict of interest. Case studies. 7 7 RESEARCH METHODS AND ETHICS IN SCIENCE 8 8 4  28/06/2024 Unit 3 – Research Design 9 Introduction “A research design is the arrangement of conditions for collection and analysis of data in a manner that aims to combine relevance to the research purpose with economy in procedure.” The research design is the conceptual structure within which research is conducted; It constitutes the blueprint for the collection, measurement and analysis of data. 10 5  28/06/2024 Introduction Design decisions happen in respect of: 1. What is the study about? 2. Why is the study being made? 3. Where will the study be carried out? 4. What type of data is required? 5. Where can the required data be found? 11 Introduction Design decisions happen in respect of: 6. What periods of time will the study include? 7. What will be the sample design? 8. What techniques of data collection will be used? 9. How will the data be analysed? 10.In what style will the report be prepared? 12 6  28/06/2024 Introduction Split the overall research design into the following parts: a) the sampling design which deals with the method of selecting items to be observed for the given study; b) the observational design which relates to the conditions under which the observations are to be made; 13 Introduction Split the overall research design into the following parts: c) the statistical design which concerns with the question of how many items are to be observed and how the information and data gathered are to be analysed; and d) the operational design which deals with the techniques by which the procedures specified in the sampling, statistical and observational designs can be carried out. 14 7  28/06/2024 Introduction Important features of a research design: a) It is a plan that specifies the sources and types of information relevant to the research problem. b) It is a strategy specifying which approach will be used for gathering and analysing the data. c) It also includes the time and cost budgets since most studies are done under these two constraints. 15 Introduction Research design must contain the following — (a) a clear statement of the research problem; (b) procedures and techniques to be used for gathering information; (c) the population to be studied; and (d) methods to be used in processing and analysing data. 16 8  28/06/2024 Introduction Need for Research Design Research design is needed because it facilitates various research operations to progress smoothly It makes research as efficient as possible, yielding maximal information with minimal expenditure of effort, time and money. 17 Introduction Need for Research Design Research design stands for advance planning of the methods to be adopted for collecting the relevant data and the techniques to be used in their analysis, keeping in view the objective of the research and the availability of staff, time and money. 18 9  28/06/2024 Introduction Features of a Good Design A good design is often characterised by flexibility, appropriateness, efficiency, economy, etc. 19 Introduction Features of a Good Design A good design…. minimises bias and maximises the reliability of the data collected and analysed. gives the smallest experimental error. 20 10  28/06/2024 Introduction Features of a Good Design Factors appropriate for consideration in a good research design: (i) the means of obtaining information; (ii) the availability and skills of the researcher and his staff, if any; (iii) the objective of the problem to be studied; (iv) the nature of the problem to be studied; and (v) the availability of time and money for the research work. 21 Introduction Important Concepts Relating to Research Design Concepts relating to designs…. 1. Dependent and independent variables: A concept which can take on different quantitative values is called a variable. Concepts like weight, height, income are all examples of variables. 22 11  28/06/2024 Introduction Important Concepts Relating to Research Design Continuous variables – phenomena which can take on quantitatively different values even in decimal points. Not all variables are continuous. Non-continuous variables – Integer values Discrete variables – statistical language for non- continuous variables 23 Introduction Important Concepts Relating to Research Design Example: Age is continuous variable, but the number of children is an example of non-continuous variable Example: if we say that height depends upon age, then height is a dependent variable and age is an independent variable 24 12  28/06/2024 Introduction Important Concepts Relating to Research Design 2. Extraneous variables: They are Independent variables that are not related to the purpose of the study, but may affect the dependent variable 25 Introduction Important Concepts Relating to Research Design Experimental Error – the effect that is noticed on the dependent variable as a result of extraneous variable(s) A study must always be so designed that the effect upon the dependent variable is attributed entirely to the independent variable(s), and not to some extraneous variable or variables. 26 13  28/06/2024 Introduction 3. Control: One important characteristic of a good research design is to minimise the influence or effect of extraneous variable(s). The technical term ‘control’ is used when we design the study to minimise the effects of extraneous independent variables. In experimental researches, the term ‘control’ is used to refer to restrain experimental conditions. 27 Introduction 4. Confounded relationship: When the dependent variable is not free from the influence of extraneous variable(s), the relationship between the dependent and independent variables is said to be confounded by an extraneous variable(s). 28 14  28/06/2024 Introduction 5. Research hypothesis: Research Hypothesis - When a prediction or a hypothesised relationship is to be tested by scientific methods. It is a predictive statement that relates an independent variable to a dependent variable. 29 Introduction 5. Research hypothesis: it must contain, at least, one Independent and one dependent variable. Predictive statements which are not to be objectively verified or the relationships that are assumed but not to be tested, are not termed research hypotheses. 30 15  28/06/2024 Introduction 6. Experimental and non-experimental hypothesis- testing research: When the purpose of research is to test a research hypothesis, it is termed as hypothesis-testing research. It can be of the experimental design or of the non- experimental design. 31 Introduction 6. Experimental and non-experimental hypothesis- testing research: Research in which the independent variable is manipulated is termed ‘experimental hypothesis- testing research’ A research in which an independent variable is not manipulated is called ‘non-experimental hypothesis- testing research’. 32 16  28/06/2024 Introduction Example 6a: Non-experimental hypothesis-testing research Suppose a researcher wants to study whether intelligence affects reading ability for a group of students and for this purpose he randomly selects 50 students and tests their intelligence and reading ability by calculating the coefficient of correlation between the two sets of scores. The independent variable, intelligence, is not manipulated. 33 Introduction Example 6b: experimental hypothesis-testing research – suppose a researcher randomly selects 50 students from a group of students who are to take a course in statistics and then divides them into two groups by randomly assigning 25 to Group A, the usual studies programme, and 25 to Group B, the special studies programme. 34 17  28/06/2024 Introduction Example 6b: At the end of the course, he administers a test to each group in order to judge the effectiveness of the training programme on the student’s performance-level. In this case the independent variable, viz., the type of training programme, is manipulated. 35 Introduction 7. Experimental and control groups: In an experimental hypothesis-testing research when a group is exposed to usual conditions, it is termed a ‘control group’, but when the group is exposed to some novel or special condition, it is termed an ‘experimental group’. 36 18  28/06/2024 Introduction 8. Treatments: The different conditions under which experimental and control groups are put are usually referred to as ‘treatments’ 37 Introduction Example 8: We want to determine through an experiment the comparative impact of three varieties of fertilizers on the yield of wheat. In that case the three varieties of fertilizers will be treated as three treatments. 38 19  28/06/2024 Introduction 9. Experiment: The process of examining the truth of a statistical hypothesis, relating to some research problem, is known as an experiment. Example: we can conduct an experiment to examine the usefulness of a certain newly developed drug. Experiments can be of two types viz., absolute experiment and comparative experiment. 39 Introduction 10.Experimental unit(s): They are pre-determined plots or the blocks, where different treatments are used. 40 20  28/06/2024 Different Research Designs Categorization of research designs: (1) Research design in case of exploratory research studies; (2) research design in case of descriptive and diagnostic research studies, and (3) research design in case of hypothesis-testing research studies. 41 Different Research Designs 1. Research design in case of exploratory research studies: Exploratory research studies are also termed as formulative research studies. The main purpose is to formulate a problem for more precise investigation or to develop the working hypotheses from an operational point of view. The major emphasis is on the discovery of ideas and insights. 42 21  28/06/2024 Different Research Designs Three methods are used in the context of research design for Exploratory Research: (a) the survey of concerning literature; (b) the experience survey and (c) the analysis of ‘insight-stimulating’ examples. 43 Different Research Designs a) Survey of Concerning Literature It is the most simple and fruitful method of formulating precisely the research problem or developing hypothesis: Hypotheses stated by earlier workers may be reviewed and their usefulness be evaluated as a basis for further research. Investigate whether the already stated hypotheses suggest new hypothesis 44 22  28/06/2024 Different Research Designs a) Survey of Concerning Literature Derive relevant hypotheses in cases where hypotheses have not yet been formulated the works of creative writers also provide a fertile ground for hypothesis formulation 45 Different Research Designs b) Experience survey It means the survey of people who have had practical experience with the problem to be studied. The researcher must prepare an interview schedule for the systematic questioning of informants. 46 23  28/06/2024 Different Research Designs c) Analysis of ‘insight-stimulating’ examples It is also a fruitful method for suggesting hypotheses for research. It is particularly suitable in areas where there is little experience to serve as a guide. This method consists of the intensive study of selected instances of the phenomenon in which one is interested. 47 Different Research Designs 2. Research design in case of descriptive and diagnostic research studies: Descriptive research studies are those studies which are concerned with describing the characteristics of a particular individual, or of a group diagnostic research studies determine the frequency with which something occurs or its association with something else. Examples of diagnostic research studies are studies concerning whether certain variables are associated 48 24  28/06/2024 Different Research Designs 2. Research design in case of descriptive and diagnostic research studies: In descriptive as well as in diagnostic studies, the researcher must be able to define clearly, what he wants to measure and must find adequate methods for measuring it along with a clear cut definition of the ‘population’ he/she wants to study 49 Different Research Designs 2. Research design in case of descriptive and diagnostic research studies: The research design must focus attention on the following: (a) Formulating the objective of the study (what the study is about and why is it being made?) (b) Designing the methods of data collection (what techniques of gathering data will be adopted?) 50 25  28/06/2024 Different Research Designs 2. Research design in case of descriptive and diagnostic research studies: (c) Selecting the sample (how much material will be needed?) (d) Collecting the data (where can the required data be found and with what time period should the data be related?) (e) Processing and analysing the data. (f) Reporting the findings. 51 Difference in research design in respect of Explorative or Formulative Fesearch and Descriptive/Diagnostic Research 52 26  28/06/2024 Different Research Designs 3. Research design in case of hypothesis- testing research studies: Hypothesis-testing research studies (generally known as experimental studies) are those where the researcher tests the hypotheses of causal relationships between variables. Such studies require procedures that will not only reduce bias and increase reliability, but will permit drawing inferences about causality. 53 Basic Principles of Research Designs Experimental is credited with Professor Fisher when he was working at Rothamsted Experimental Station (Centre for Agricultural Research in England) He enumerated three principles of experimental designs: (1) the Principle of Replication; (2) the Principle of Randomization; and the (3) Principle of Local Control. 54 27  28/06/2024 Basic Principles of Research Designs The Principle of Replication The experiment should be repeated more than once. Each treatment is applied in many experimental units instead of one. By doing so the statistical accuracy of the experiments is increased. 55 Basic Principles of Research Designs The Principle of Randomization It provides protection, when we conduct an experiment, against the effect of extraneous factors by randomization. This principle indicates that we should design or plan the experiment in such a way that the variations caused by extraneous factors can all be combined under the general heading of “chance.” 56 28  28/06/2024 Basic Principles of Research Designs The Principle of Local Control It is another important principle of experimental designs. Under the principle the extraneous factor, the known source of variability, is made to vary deliberately over as wide a range as necessary. This needs to be done in such a way that the variability it causes can be measured and hence eliminated from the experimental error. 57 Important Experimental Designs Experimental design refers to the framework or structure of an experiment Experimental designs into two broad categories, viz., a) informal experimental designs and b) formal experimental designs. 58 29  28/06/2024 Important Experimental Designs a) Informal experimental designs are those designs that normally use a less sophisticated form of analysis based on differences in magnitudes b) Formal experimental designs offer relatively more control and use precise statistical procedures for analysis. 59 Important Experimental Designs Important experiment designs are as follows: (a) Informal experimental designs: (i) Before-and-after without control design. (ii) After-only with control design. (iii) Before-and-after with control design. 60 30  28/06/2024 Important Experimental Designs Important experiment designs are as follows: (b) Formal experimental designs: (i) Completely randomized design (C.R. Design). (ii) Randomized block design (R.B. Design). (iii) Latin square design (L.S. Design). (iv) Factorial designs. 61 Factorial Design Objectives Define factorial design; Describe the terms related to factorial design; Formulate factorial design; Describe graphically the results of factorial experiment; and Identify the advantages and limitations of factorial design. 62 31  28/06/2024 Factorial Design Meaning of Factorial Design A factorial design is one in which two or more variable or factors are employed in such a way that all the possible combinations of selected values of each variable are used – Mcburney & White, 2007 63 Factorial Design Terms Related to Factorial Design Factor The term factor is broadly used to include the independent variable that is manipulated by the investigator in the experiment or that is manipulated through selection. 64 32  28/06/2024 Factorial Design Terms Related to Factorial Design Main Effect This is the simplest effect of a factor on a dependent variable. It is the effect of the factor alone averaged across the level of other factors. 65 Factorial Design Terms Related to Factorial Design Main Effect According to Mcburney & White (2007) main effect in a factorial experiment, the effect of one independent variable, averaged over all levels of another independent variable. 66 33  28/06/2024 Factorial Design Terms Related to Factorial Design Interaction According to Mcburney & White (2007) Interaction means when the effect of one independent variable depends on the level of another independent variable. 67 Factorial Design Terms Related to Factorial Design Interaction Example: A cholesterol reduction clinic has two diets and one exercise regime. It was found that exercise alone was effective and diet alone was effective in reducing cholesterol levels (main effect of exercise and main effect of diet). 68 34  28/06/2024 Factorial Design Terms Related to Factorial Design Interaction Example: Also for those patients who didn’t exercise, the two diets worked equally well (the main effect of diet); Those who follow diet A and exercised got the benefits of both (main effect of diet A & main effect of exercise). 69 Factorial Design Terms Related to Factorial Design Interaction Example: However it was found that those patients who followed diet B and exercised got the benefit of both plus a bonus, an interaction effect (main effect of diet B, main effect of exercise plus an interaction effect of diet and exercise). 70 35  28/06/2024 Factorial Design Terms Related to Factorial Design Types of Interaction 1) Antagonistic interaction: When main effect is non- significant and interaction is significant. In this situation the two independent variables tend to reverse each others effect. 2) Synergistic interaction: When higher level of one independent variable enhances the effect of another independent variable. 71 Factorial Design Terms Related to Factorial Design Types of Interaction 3) Celling effect interaction: When the higher level of one independent variable reduces the differential effect of another variable. That is one variable has a smaller effect when paired with higher level of a second variable (Mcburney & White, 2007). 72 36  28/06/2024 Factorial Design Terms Related to Factorial Design Randomization Randomisation is the process by which experimental units are allocated to treatment; that is by a random process and not by any subjective process. The treatment should be allocated to units in such a way that each treatment is equally likely to be applied to each unit. 73 Factorial Design Terms Related to Factorial Design Blocking This is the procedure by which experimental units are grouped into homogenous cluster in an attempt to improve the comparison of treatment by randomly allocating the treatment within each cluster or block. 74 37  28/06/2024 Factorial Design Simple Two Factor Design In the two factor design we have two independent variables, each of which has two values or levels. This is known as two by two (2x2) factorial design because of the two levels of each variables. 75 Factorial Design Simple Two Factor Design Layout of Factorial Design 76 38  28/06/2024 Factorial Design Simple Two Factor Design Layout of Factorial Design If we have two levels of one variable and three of another variable we would have two by three (2x3) factorial design. 77 Factorial Design Simple Two Factor Design Layout of Factorial Design Two by three (2x3) factorial design. 78 39  28/06/2024 Factorial Design Example 1 An experiment is being conducted to pyrolyse plastic waste (HDPE, LDPE) into fuel (gasoline and diesel).It is known that catalysts improve product selectivity. Another factor, temperature, also affects the product distribution. We want to conduct an experiment to study the effects of these two factors, catalyst type and temperature, on the product distribution (amount of liquid fuel, gas, and char). We are using a 3x3 factorial design. 79 Factorial Design 3x3 Factorial Design – using 2 factors (Reaction Temperature and Type of Catalyst) Temperature Factors T1 T2 T3 C1 T1C1 T2C1 T3C1 Catalysts C2 T1C2 T2C2 T3C2 C3 T1C3 T2C3 T3C3 80 40  28/06/2024 Factorial Design Advantages of Fractorial Design Factorial design enables the researcher to manipulate and control two or more independent variables simultaneously. By this design we can study the separate and combined effect of number of independent variables. Factorial design is more precise than single factor design (Kerlinger, 2007). 81 Factorial Design Advantages of Fractorial Design By factorial design we can find out the independent or main effect of independent variables and interactive effect of two or more independent variables. The experimental results of a factorial experiment are more comprehensive and can be generalised to a wider range due to the manipulation of several independent variables is one experiment. 82 41  28/06/2024 Factorial Design Limitations When we have more than three independent variables each with three or more levels are to be manipulated together, the experimental setup and statistical analysis become very complicated. In factorial experiments when the number of treatment combinations or treatments become large, it becomes difficult for the experimenter to select a homogeneous group. 83 Factorial Design Summary Factorial designs are employed when one wants to study the independent and joint effect of two or more independent variables. There are different types of interaction such as antagonistic, synergistic and ceiling effect. Factorial designs may be conducted as within subject, between subject or they may be used in mixed experiments that have one within subject and one between subject variable. 84 42  28/06/2024 Factorial Design Summary Factorial design: Research design that involve all combination of at least two values of two or more independent variables. Main effect: The effect of one independent variable averaged over all levels of another independent variable. Interaction: When the effect of one independent variable depends on the level of another independent variable. 85 Unit 3 – Research Design 86 43