Has PDF. Publication Type. More Filters. Faculty members in higher education are called to be effective researchers; however, there is limited research examining the research development of Ph. The cross-sectional, correlational … Expand. An educational dilemma: Are educational experiments working?
The main aim of this study is to investigate the biased effects which affect scientific researches; although most of the researchers ignore them, and make criticism of the experimental works in the … Expand. View 1 excerpt, cites background. Innovation and creativity in European society are fostered via a dynamic and flexible European higher education based on the integration between education and research at all levels Communique, … Expand.
View 3 excerpts, cites background and methods. The P. Embarking in an educational research paper is one of the daunting processes any scholar can go through. And the process if even harder for novice education students who wander through the plethora of … Expand. Response to intervention RTI has received considerable attention from both researchers and practitioners as a schoolwide model for service delivery.
However, research is limited on RTI applications … Expand. This chapter presents a review of research in online problem-based learning PBL in teacher education.
The goal of this chapter is to present a critical analysis of the body of research that has … Expand. Integration of WebQuest in a social studies course and motivation of pre-service teachers.
There were … Expand. Highly Influenced. View 5 excerpts, cites methods and background. Foreword As part of our ongoing efforts to enhance the ability of our constituents and friends to make good use of the research in education in crafting policy alternatives, the Education Commission … Expand.
View 1 excerpt, cites methods. Introduction Since the beginning of the formalized education, research has been used to improve education and to determine in a wide range of situations. Fo r example, if the available sample fo r stud ying the impact o f co llege is the gro up o f alumni w ho return on alumni day, their responses w ould probably be quite different from those of all alumni.
Similarly, research on effective teaching that depends on teachers in a particular geographic area, be- cause they are available, may result in different findings than research done in other geographic areas.
A lthough w e need to be very way of convenience samples, often this is the only type of sampling possible, and the primary purpose of the research may not be to generalize but to better understand relation- ships that may exist. Suppose a researcher is investigating the relation- ship betw een creativity and intelligence, and the only available sample is a single elementary school.
The study is completed, and the resulu indi- cate a mo d erate relatio nship: Child ren w ho have higher intelligence tend to be more creative than children w ith low er intelligence.
Because there w as no probability sampling, should w e ignore the findings or sug- gest that the results are not valid or credible? That decision seems overly harsh. It is more reasonable to interpret the results as valid for children similar to those studied.
For example, if the school serves a low socio- economic area, the results w ill not be as useful as those from a school that sew es all socioeconomic levels. The decision is not to dismiss the findings but to limit them to the type of subjects in the sample.
As more and more research accumulates w ith different convenience samples, the overall credibility of the results is enhanced. If some type of probability sampling procedure was used it will be described.
Thus, in the absence of such particulars you can assume that the sample was an available one. The following ex- amples are typical. From the oool of ! Thirty-five of these students also participated in the!
All kindergarten and. Of 22 teachers invited to. To study effective schools it may be most informative to interview key personnel, such as the principal and teachers who have been in the school a num- ber of years. In qualitative research, o n the o ther hand , so me type o f purpo sive sam- pling is almost alw ays used. Purposive sampling is illustrated by the fol- low ing excerpts. Further discussion of sampling for qualitative studies is included in Chapter All were women with ,I at least 10 years of teaching experience at the elementaty level.
Teach- ; ers were recruited to include as wide a range of backgrounds and ap- proaches in the teaching of mathematics as possible. Some were recom- :. Others agreed to participate in the study because they were inter- ested but did not consider themselves to be particularly outstanding : mathematics teachers.
Selection was gov- , erned by the need to capture the variability of retention practices within 1 the district. Different co mpo site pro files o f majo r gro ups in the population are identified, and then subjects are selected, nonran- domly, to represent each group. A type of quota sampling that is com- m o n in ed ucatio nal research is co nd ucted to rep resent g eo g rap hic areas or types of communities, such as urban, rural, and suburban.
Typ ically, a state is divided into distinct geographic areas, and cases are se- lected to represent each area. A s in availability and purposive sampling, there is a heay reliance on the decisions of the researcher in selecting the sample, and appropriate caution should be used in interpreting the RSUltr. Knowledge of Sampling Procedures To understand how sampling may affect research it is essential to know the characteristics o f d ifferent sampling pro ced ures.
This kno w led ge w ill help you interpret the sample that is used. You should first be able to identify the sampling procedure and then evaluate its adequacy in ad- dressing the research problem and in supporting the conclusions.
It w ill be helpful to know the strengths and w eaknesses of each sampling pro- cedure, as summarized in Table 4. Volunteer Samples A continuing problem in educational research, as w ell as in most social science research, is the use o f vo lunteers as subjects. It is w ell d o cu- mented that vo lunteers d iffer fro m no nvo lunteers in impo rtant w ays.
Volunteers tend to be better educated, higher socioeconomically, more intelligent, mo re in need o f so cial appro val, mo re so ciable, mo re un- co nventio nal, less autho ritarian, and less co nfo rming than nonvolun- teers. Obviously, volunteer samples may respond differently than non- volunteers because of these characteristics. One w ay volunteers are used is in survey research. The researcher typically sends questionnaires to a sample of individuals and tabulates the respo nses o f tho se w ho return them.
Often the percentage o f the sample returning the questio nnaire w ill be 50 to 60 percent o r even low er.
In this circumstance the sample is said to be biased in that the re- sults may not be representative of the population. Thus, the nature of the results depends on the types of persons w ho respond, and generaliz- ability to the target population is compromised. The specific effect that a biased sample has on the results depends on the nature of the study. For example, a study of the relationship betw een educational level and occupational success w ould be likely to show only a small relationship if only those w ho are most successful respond.
Without some subjects w ho are not successful in the sample, success cannot be accurately related to the level of education. If a survey of teachers is conducted to ascertain their general kno w led ge and read ing and w riting skills, the results w ould probably be higher than the true case because of the tendency of volunteers to be better educated.
Usually representative 1. Requires numbering each of the population element in the population 2. Easy to analyze and 2. Larger sampling error interpret results than in stratified sampling 3. Easy to understand Systematic 1. Periodicity in list of population elements 2. Simplicity of drawing sample Proportional 1. Requires subgroup stratified random identification of each population element 2.
Allows subgroup 2. Requires knowledge of comparisons the proportion of each subgroup in the population 3. Usually more 3. May be costly and representative than difficult to prepare lists of simple random or population elements in systematic each subgroup.
Fewer subjects needed 5. Results represent population without weighting Disproportional 1. Assures adequate 2. Requires proper numbers of elements weighting of subgroup to in each subgroup represent population 3. Less efficient for estimating population characteristics Cluster 1.
LOW cost 1. Less accurate than simple random, systematic, or stratified 2. Requires lists of 2. May be difficult to collect elements data from all elements in each cluster 3. Efficient with large 3. Less costly 1. Difficult to generalize to other subjects 2. Less timeconsuming 2.
Less representative of an identified population 3. Ease of administration 3. Results dependent on unique characteristics of the sample 4.
Usually assures high participation rate 5. Generalization possible to similar subjects Purposive 1. Adds credibility to qualitative research 3. Assures receipt of needed information Quota 1. Usually more time- population than consuming than convenience or convenience or purposive purposive Volunteers are commonly used in research because the availability of subjects is often limited by time and resources.
There have been thou- sands of studies with teachers who volunteer their classes for research. Much research on school-age children requires written permission from parents, and this necessity can result in a biased sample. Sample Size An important consideration in judging the credibility of research is the size of the sample. Most researchers use general rules of thumb in their studies, such as having at least 30 subjects for correlational research, and at least 15 subjects in each group in an experiment.
In surveys that sample a population, often a vely small percentage of the population must be sampled, for example, less than 5 or even 1 percent. Of course if the SW- vey sample is too small, it is likely that the results obtained cannot char- acterize the population. Formal statistical techniques can be applied to determine the number of subjects needed, but in most educational studies these techniques are not used. In educational research a major consideration with sample size is concluding that a study with a relatively small sample that found no dif- ference or no relationship is true.
For example, suppose that you are studying the relationship between creativity and intelligence and, with a sample of 20 students, found that there was no relationship. Is it rea- sonable to conclude that in reality there is no relationship?
Probably not, since a probable reason for not finding a relationship is because such a small sample was used. In addition to the small number of sub jects, it is likely that there may not be many differences in either creativ- ity or intelligence, and without such differences it is impossible to find that the two variables are related. That is, with a larger sample that has different creativity and intelligence scores, a relationship may exist.
This problem, interpreting results that show no difference or relation- ship with small samples, is subtle but very important in educational re- search since so many studies have small samples. Also, a sample that is not properly drawn from the population is misleading, no matter what the size. Subject Motivation Sometimes subjects will be motivated to respond in certain ways.
Clues for this phenomenon will be found in the description of how the sub jects were selected. For example, if a researcher was interested in study- ing the effectiveness of computer simulations in teaching science, one approach to the problem would be to interview teachers who used com- puter simulations. The researcher might even ivant to select only those science teachers who had used the simulations more than two years. It is not hard to understand that the selected teachers, because they had been using the simulations, would be motivated to respond favorably tc- ward them.
Sampling Bias In selecting a sample from a population there is alw ays some degree of sampling error. This error is the discrepancy betw een the true value of a variable fo r the po pulatio n and the value that is calculated fro m the sample, and it is expected and precisely estimated as part of sampling.
A different type of error is due to sampling bias, a type of sampling error Sampling bias: Sampling error that is controlled or influenced by the researcher to result in misleading caused bY the researcher.
Occasionally researchers w ill deliberately skew the sampling. The most obvious deliberate bias is selecting only those subjects that w ill respond in a particular w ay to support a point or result. For instance, if a researcher is measuring the values of college students and wants to show that the stud ents are co ncerned abo ut helping o thers and being in- volved in community service, bias w ould result if the researcher deliber- ately selected students in education or social w ork and ignored majors that might no t be so altruistically o riented.
Selecting friend s o r co l- leagues may also result in a biased sample. A n even more flagrant type of bias occurs w hen a researcher discards some subjects because they have not responded as planned or keeps adding subjects until the de- sired result is obtained. In qualitative studies the researcher needs to be particularly care- ful abo ut po ssible unintend ed bias if sampling changes d uring the study. Bias can also result from selecting subjects from different popula- tions and assigning them to different groups for an experiment or com- parison.
Suppose a researcher used graduate sociology students to re- ceive a treatment in an experiment and graduate psychology students as a control group. Even if the samples w ere selected randomly from each po pulatio n, d ifferences in the po pulatio ns, and co nsequently samples, in attitudes, values, know ledge, and other variables could explain w hy certain results w ere obtained.
The subjects in tbe study should be clearly described, and the description should be specific and detailed. The population should be clearly defied. It is especially impor- tant to provide a specific definition of the population in studies using probability sampling. The characteristics of each stratum in a stratified sampling procedure should also be included. The method of sampling should be dearly described.
The spe- cific type of sampling procedure, such as simple random, stratified, clus- ter, or convenience, should be explicitly indicated in sufficient detail to enable other researchers to replicate the study. The return rate sho uld be ind icated and analyzed. In stud ies that survey a population, the return rate of questionnaires should be in- dicated.
If the return rate is less than 60 percent, the researcher should analyze the implications of excluding a significant portion of the popu- lation. This step is accomplished by comparing the nonrespondents to those w ho returned the questionnaires to determine if there are signifi- cant differences betw een the groups. The selection of subjects should be free of bias.
The procedures and criteria for selecting subjects should not result in systematic error. Selection procedures should be appropriate for the problem be ing investigated. If the problem is to investigate science attitudes of mid- dle school students, it w ould be inappropriate to use high school stu- denw as subjects. If the p ro blem is to stud y the characteristics o f effective teaching, the w ork of student teachers w ould probably not be very representative of effective teaching behaviors.
There should be an adequate number of subjects. If the sample is selected from a population, the sample size must be large enough to represent the po pulatio n accurately. Studies w ith small samples that report no differences or no relationships should be view ed w ith caution since a higher number or a better selection of subjects may result in meaningful d ifferences o r relatio nships.
Qualitative studies should have informative and knowledgeable subjects. Since the purpose of qualitative research is to understand a phenomenon in depth, it is important to select subjecti that w ill provide the richest info rmatio n. The researcher sho uld ind icate the criteria used to select subjecw, the reasons w hy these particular individuals w ere selected, and the strategies used for selecting subjects during the study.
Subject selection. Participants from whom data are gathered. Group to whom results are generalized. Described by delimiting variables. Procedures for selecting subjects.
Probability sampling. Subjects selected from a larger population. Always some error in sampling. Simple random sampling. Every member of the population has the same chance of being selected. Systematic random sampling. Subjects are selected without numbering each member of the population. Periodicity may cause bias in the result. Stratified random sampling. Divides population into groups before sample selection. Often provides a more accurate sample. Desirable for comparing subgroups.
Proportional or disproportional selection. Cluster sampling. Naturally occurring groups of subjects are selected at ran- dom. Usuall; less accurate. Nonprobability sampling. Very common and over time results in generalizable con- clusions. Convenience samples.
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