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CAWM-MWEKA Technician Certificate in Wildlife Management MODULE: BASIC STATISTICS By Rudolf Filemon February, 2014. DATA COLLECTION. Introduction The task of data collection begins after a research problem has been defined and research plan chalked out.
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CAWM-MWEKA Technician Certificate in Wildlife Management MODULE: BASIC STATISTICS By Rudolf Filemon February, 2014
DATA COLLECTION Introduction • The task of data collection begins after a research problem has been defined and research plan chalked out. • While deciding about the method of data collection to be used for the study, the researcher should keep in mind two types of data based on their sourced viz., primary and secondary. • The primary data are those which are collected afresh and for the first time, and thus happen to be original in character.
Introduction to Data Collection Cont.. • The secondary data, on the other hand, are those which have already been collected by someone else and which have already been passed through the statistical process. • The data collection process particularly the primary one can be relatively simple or complex depending on the type of data collection tools required and used during the research. To derive conclusions from data, we need to know how the data were collected; that is, we need to know the method(s) of data collection.
Data Collection Tools • Data collection tools are instruments used to collect information for assessments, survey and evaluations. The data collection tools need to be strong enough to support what the evaluations find during research. • In statistical terms here are a few examples of data collection tools used within three main categories. There are four main methods of data collection.
Data Collection Tools Cont.… These include but not limited to the following; • Census • Sample survey • Experimental data collection • Observational data collection method
Census • A census is a study that obtains data from every member of a population. In most studies, a census is not practical, because of the cost and/or time required. • This method of data collection is very expensive (tedious, time consuming and costly) if the number of elements (population size) is very large. To understand the scope of how expensive it is, think of trying to count all the ten year old boys in the country. That would take a lot of time and resources, which you may not have.
Sample survey • A sample survey is a study that obtains data from a subset of a population, in order to estimate population attributes. • Thus, sample data collection, is commonly just referred to as sampling. It is a method which collects data from only a chosen portion of the population. • This can save resources and time by only collecting data from a small part of the population but raises questions of whether sampling is accurate (representative) or not.
Experiment • An experiment is a controlled study in which the researcher attempts to understand cause-and-effect relationships. The study is "controlled" in the sense that the researcher controls (1) how subjects are assigned to groups and (2) which treatments each group receives. • Experimental data collection involves one performing an experiment and then collecting the data to be further analyzed. Experiments involve tests and the results of these tests are your data.
Experiment Cont.… • In the analysis phase, the researcher compares group scores on some dependent variable. Based on the analysis, the researcher draws a conclusion about whether the treatment (independent variable) had a causal effect on the dependent variable. • Experimental data collection is useful in testing theories and different products and is a very fundamental aspect of mathematics and all science as a whole.
Observational study • Observational data collection method involves not carrying out an experiment but observing without influencing the population at all. Observational data collection is popular in studying trends and behaviors of society where, for example, the lives of a bunch of people are observed and data is collected for the different aspects of their lives • Like experiments, observational studies attempt to understand cause-and-effect relationships. However, unlike experiments, the researcher is not able to control (1) how subjects are assigned to groups and/or (2) which treatments each group receives.
Data Collection Methods: Pros and Cons • In general, each method of data collection has advantages and disadvantages. • Resources: When the population is large, a sample survey has a big resource advantage over a census. A well-designed sample survey can provide very precise estimates of population parameters - quicker, cheaper, and with less manpower than a census. • Generalizability: The appropriateness of applying findings from a study to a larger population. Generalizability requires random selection.
Data Collection Methods: Pros and Cons Cont.… • Note: Observational studies do not feature random selection; so generalizing from the results of an observational study to a larger population can be a problem. • Causal inference. Cause-and-effect relationships can be teased out when subjects are randomly assigned to groups. Therefore, experiments, which allow the researcher to control of variable to treatment groups, are the best method for investigating causal relationships.
Significance of Data Collection • Collecting good quality data plays a vital role in supplying objective information for the problems under study so that some analytical understanding of the problems and hence solutions can be obtained. • It is part of the scientific process: data collection and analysis. Without proper data collection and analysis there can be no definitive answer to the original research question.
Significance of Data Collection Cont.… • Data collection, bias free from the researcher is crucial - it will effect the outcome of the assessment or survey. • Data collection is significant as the basis for planners to work from as data set basis and see what the facts are and what are not.
Forms of Data Collected • Data collected from any study or survey may take the form of qualitative or quantitative. • Qualitative data: classification is made according to some attributes or quality such as sex, religion, etc. • Quantitative data: it refers to classification of data according to some characteristics that can be measured such as weight, height etc. • Note: the type of study and research goal/hypotheses/question dictate form of data to be collected
Problem Which of the following statements are true? • A sample survey is an example of an experimental study. • An observational study requires fewer resources than an experiment. • The best method for investigating causal relationships is an observational study. • I only • II only • III only • All of the above. • None of the above.
