Practical Research 2 - Quarter 2 Module 2 - Sample and Sampling Procedures PDF
Document Details
Uploaded by FastPacedIndium4994
2020
Maria Cristina Balmores
Tags
Related
- Practical Research 2 Quarter 2 Modules PDF
- Chapter 3 Research Methodology PDF
- Quantitative Research Concepts Overview PDF
- Quarter 2 Understanding Data and Ways to Systematically Collect Data PDF
- Quantitative Research Designs and Sampling Procedure PDF
- Sampling Procedure for Quantitative Research PDF
Summary
This module covers sample and sampling procedures in quantitative research. It provides examples of practical research studies and discusses various sampling methods, including probability and non-probability techniques, in qualitative research.
Full Transcript
Practical Research 2 Quarter 2 – Module 2: Sample and Sampling Procedures Practical Research 2 – SHS Alternative Delivery Mode Quarter 2 – Module 2: Sample and Sampling Procedures First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Gove...
Practical Research 2 Quarter 2 – Module 2: Sample and Sampling Procedures Practical Research 2 – SHS Alternative Delivery Mode Quarter 2 – Module 2: Sample and Sampling Procedures First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education OIC-Schools Division Superintendent: Carleen S. Sedilla CESE OIC-Assistant Schools Division Superintendent and OIC-Chief, CID: Jay F. Macasieb DEM Development Team of the Module Writer: Maria Cristina Balmores Editor: Edwin I. Salviejo EdD Reviewer: Ma. Cecilia Julieta G. San Jose Layout Artist: Charry Vida R. Cervantes Management Team: Neil Vincent C. Sandoval Education Program Supervisor, LRMS Edwin I. Salviejo EdD Division Science Coordinator/School Principal I \ Printed in the Philippines by the Schools Division Office of Makati City through the support of the City Government of Makati (Local School Board) Department of Education – Schools Division Office of Makati City Office Address: Gov. Noble St., Brgy. Guadalupe Nuevo City of Makati, Metropolitan Manila, Philippines 1212 Telefax: (632) 8882-5861 / 8882-5862 E-mail Address: [email protected] What I Need to Know This module was designed and written with you in mind. It is here to help you master the Quantitative Research Methodology. The scope of this module permits it to be used in many different learning situations. The language used recognizes the diverse vocabulary level of students. The lessons are arranged to follow the standard sequence of the course. But the order in which you read them can be changed to correspond with the textbook you are now using. After going through this module, you are expected to: 1. describe sampling procedure and sample; What I Know Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 1. What would a group of students be doing if they are encoding the answers of the respondents to a survey using Excel spreadsheets? a. Defining a problem. c. Processing and organizing data. b. Observing and collecting data d. Testing a hypothesis. 2. Which of the following quantitative research designs is most appropriate for a study that involves two or more experimental set-ups using different groups of test organism/respondents in a field study? a. Correlational Design c. Quasi-Experimental b. Descriptive Survey d. True Experimental study 3. Which of the following will give a more “accurate” representation of the population from which the sample has been taken? a. A large sample based on convenience sampling. b. A large sample based on simple random sampling. c. A small sample based on quota sampling. d. A small sample based on simple random sampling. 4. What type of data will you generate if you will rate the difficulty of this test by choosing one of the five options: very difficult/ difficult/ average/ easy/ very easy? a. Interval b. Nominal c. Ordinal d. Ratio 5. Which hypothesis is hoped to be rejected? a. Alternative hypothesis c. Statistical hypothesis Lesson Sample and Sampling 1 Procedures What’s In In the previous lesson, you learned about the first section of the methodology for quantitative research, which is the Research Design. In this lesson, you will learn about the sample and how to select them from the population using varied and appropriate sampling methods and techniques. 1 What’s New Samples and Sampling Before we start a new lesson, read some portions of the research samples and try to answer the questions that follow each example. Example Study 1 The choice of a course and which school to enter in college is one of the major decisions faced by graduating students which is an important element of their learning process. The course and school selection decision will most likely define their future success. The paper was aimed at assessing the students’ course and school preference using a descriptive research design. A survey was administered to respondents totaling 2,231 comprised of grade 12 students enrolled in La Consolacion University Philippines (LCUP) during the second semester of school year 2017-2018. Findings revealed that Accountancy, Education and Hotel and Restaurant Management were the three courses most preferred. However, LCUP was not the top school of choice among respondents. Seven out of ten most preferred courses are current offerings at LCUP, three of which are board courses. The provision of a more intensive internal marketing program is suggested. Likewise, a study on the impact of programs and services and their influence on career and school selection decisions may be conducted to determine which program or service made available to senior high students singly or in combination are determinants of their retention. Follow-up research on the reasons why students choose a course or a school may be also be considered. Source: (Dayao, Ryan and Olivia Almario, 2017)Copy Right, IJAR, 2017... All rights reserved. What is the population? _______________________________________________________ What is the sample? __________________________________________________________ How would you describe the sample? __________________________________________ Example Study 2 Making of the Fiberglass Reinforcement Product The researchers followed the procedure that was recommended by Victor Mesias, a sales representative at the Polymer Products (Phil.) Inc. In making the commercial fiberglass, the molder was first surrounded by a plastic acetate sheet and two sheets of chopped strand mat with the same dimensions. 4o ml of resin was mixed with approximately 1 cc of blue toner and 1.3 % of MEKP hardener. After mixing, it was poured in the molder and was covered by a plastic acetate sheet. The sample was left to dry for 20-30 minutes under room temperature. For the experimental groups, the water hyacinth fibers were added between the two sheets of chopped strand mat before adding the resin and hardener mixture. The sample was also left to dry for 20-30 minutes under room temperature. Breaking Load in Tension Table 1. Data Analysis of Control Group Table 2. Data Analysis of one gram Water Hyacinth Fiber Reinforcement NO. Width Thickness Maximum Observation ONE GRAM (mm) (mm) Load (N) NO. Width Thickness Maximum Observation 1 23.33 7.013 3044.93 Sample is (mm) (mm) Load (N) brittle. 1 23.07 7.857 4464.29 Sample is 2 20.43 7.7 3039.49 Sample is brittle. brittle. 2 24.15 8.694 4522.48 Sample is 3 20.93 8.248 2111.41 Sample is brittle. brittle. 3 25.83 7.786 3887.04 Sample is 4 20.48 6.591 3462 Sample is brittle. brittle. 4 24.97 8.447 4009.97 Sample is 5 21.35 8.598 2501.09 Sample is brittle. brittle. 5 24.23 7.37 4110.03 Sample is Mean 21.3 7.63 2831.78 brittle. S.D. 1.19 0.83 527.74 Mean 24.45 8.031 4198.76 Source: (dela Vega, et al, 2015) S.D. 1.03 0.53 281.06 2 What is the population? __________________________________________________________ What is/are the sample/s? _______________________________________________________ How would you describe the sample/s? ___________________________________________ What is It Sample A basic element of the research problem is the Population or Universe. It is important because the data you need to gather for your investigation will be coming from the members of the population. A population is an aggregation or group of objects, people, events or places that has the qualities, characteristics, properties or values that a researcher needs for his study. Each member of a population is called an element, which may be called units or subjects (Caintic and Cruz,, 2008). Let us say all the students in ABC Senior High School is the population. A student from this population is the element. Since including all the students in the study is difficult (and sometimes costly), you can get a representative of the student population. This representative units of the population of students is the sample you will use for your study. Choosing the sample students from the population of students is the process called sampling. It is important to note that the sample MUST possess the characteristics or qualities needed so that the data to be collected is valid and reliable. For example, if a researcher wants to test the antifungal capability of a plant’s extract, then the sample plant being studied must have antifungal component in its extract. In the description of the sample plant, this information is validated through relevant and updated literature review and authentication of the plant’s identity through proper institutions. Another example is a researcher investigating the effect of part-time employment to academic performance of senior high school students, then the sample participants or respondents have to be senior high school students who are actually working in part-time jobs. This information is also validated by the school’s list or registered learners and employment certification. Sampling method. This refers to the way the samples are chosen from the population. Probability or random sampling. This method follows a systematic way wherein every element of a population has a chance of being included in the sample. Non-probability or Nonrandom sampling. This method does not ensure that every element of the population may be selected as a part of the sample. The selection of the sample is based on the need of the study. Sampling Procedures or Techniques A. Probability or random sampling. Pure random sampling. Otherwise known as “fishbowl” method or “lottery” method. Systematic sampling. This technique uses a formula to decide the elements to be included in the: n=N/k, where n=nth element in the population; N is the population and k is the sample size. So if N is 100 and k is 20, then n=100/20, therefore n is 5. Every 5th element of the population is selected for the sample. Stratified sampling. If the population can be divided into subgroups or stratum that are more or less homogeneous or have shared similarities, then this technique is useful. For example, grade 7 junior school students may be grouped in strata of different sections. Each section or class has to be represented in the sample. 3 Table 1 First year students who are sectioned according to ability. Number 20% Section 1 male 20 4 female 30 6 Section 2 male 20 4 female 25 5 Section 3 male 18 4 (rounded) female 27 5 (rounded) TOTAL 140 28 Cluster sampling. When the target respondents of a study is spread across a geographical location, and the respondents are quite heterogeneous, this techniques may be used. For example, a researchers needs to interview coffee drinkers whose age range are from 21 to 45 and residents of Zone 3 of Barangay Barako. The groups he may form may be based on residents by street or by block. Multi-stage sampling. This is like an extension of cluster sampling because it can cover a wider geographical area. The stage may start with the barangay level, then municipal or city, provincial, regional, and national levels. B. Non-probability or Nonrandom sampling. Accidental sampling. In this type of sampling, there is no system being followed. The researcher includes anyone he meets along the way as his sample participants. Convenience sampling. This type of sampling is the fastest and easiest because the researcher will contact his friends or anybody who is in his phone directory to get their responses to a survey or interview. Online surveys use this technique. Judgmental or purposive sampling. This technique is used when the researcher needs to look for subjects based on the purpose of his study. For example, the grade 11 General Academics Strand (GAS) students would like to find out the different career choices of senior high school students enrolled in the GAS strand since the students enrolled in this strand are those who have not clearly decided on the career path to take. Purposively, only GAS students should be selected as sample respondents. Quota sampling. This technique is used by the researcher if he needs participants with specific characteristics but quite hard to reach or find, so he sets a specific number or quota to make his findings reliable. For example, is finding identical twins for a comparative study. Snowball sampling. This technique will require the researcher to use his network or find one respondent who can refer other possible respondents for the study. Usually, a researcher uses this technique when he has limited knowledge on how to get hold of his needed individual or group respondents. Determination of Sample Size The size of the sample is important for the researcher because a very large sample size could mean a waste of resources, but a very small sample size may produce unreliable data. According to Sevilla et al (2001), to determine the sample size for your study, you can use Slovin’s (1960) formula: n= N where: n = sample size 1 + Ne2 N = population size e = desired margin of error According to Sevilla et al (2001), the margin of error is the allowable percentage of not being able to get the exact value needed because of the use of the sample instead of the population. According to Prieto, Naval and Carey (2017), if you use a confidence level of 95%, then the margin of error is 5%. A 99% confidence interval gives a 1% margin of error. Calderon and Gonzales (1993) say that the margin of error should not be higher than 5%. 4 For example, you plan to conduct study involving the 1,500 Grade 11 STEM students of ABC Senior High School. How many participant students do you need using a margin of error of 5 %? Given: N = 1,500 e=5% Solution: n= N___ 1 + Ne2 n = ____1,500_____ 1 + (1,500)(.05)2 = ____1,500_____ 1 +3.75 =____1,500_____ 4.75 n = 315.79 or 316 STEM students After determining how many Grade 11 STEM students you need for your study, you can now apply the appropriate sampling method and technique to select the 316 student participants from the population of 1,500 Grade 11 STEM students of ABC Senior High School. (Hint: What does your most relevant Related Study in your Literature Review tell you?) In the book of Sevilla et al (2001), Gay (1976) suggests the following minimum acceptable sample sizes for some types of research: 1. Descriptive research – 10% of the population. If the population is smaller, 20% is acceptable. 2. Correlational study – 30 subjects 3. Ex Post Facto – 15 subjects per group 4. Experimental research – 15 subjects per group What’s More Activity 2.1 Understanding Sample and Sampling Techniques Given below are abstracts of some sample research studies. Read and analyze each abstract by identifying what is being asked and writing your answers on the on the spaces provided for each item. Research Example 1: I selected Umeå University because I wanted to test the relationship between customer satisfaction and service quality with respect to SERVQUAL dimensions in a school. There was no special criterion for choosing this school but I selected the school because it was more convenient for me to get the data. Moreover, at the University one could get matured students as customers who could be able to evaluate the services rendered to them other than other preliminary schools. Also, I selected Forex bank because I wanted to test the relationship between customer satisfaction and service quality with respect to SERVQUAL dimensions in a bank. There was no special criterion of choosing this bank but I selected the bank because it was the only bank that gave me quick response when I requested to get information from its customers. As a bank like this, I could get matured people as customers who could be able to evaluate the services rendered to them, since there is no customer below 18years. I selected ICA Ålidhem Centrum because I needed to use a shop. I wanted to test the relationship between customer satisfaction and service quality with respect to SERVQUAL dimensions in a shop. There was no special criterion of choosing this shop but I selected the shop because it was the only shop that gave me quick response to use its customer’s just like with Forex bank because I needed any shop. Thus the respondents from these chosen organizations were just customers available to me as a researcher but not necessarily a representative of the customer population, Although the findings of this kind of sampling strategy 5 could be interesting, the problem is that it is difficult to generalize the findings but the findings could provide a springboard for further research or allow links to be forged with existing findings in an area. (Bryman & Bell, 2003, p. 105). Moreover, Bryman & Bell stated that this samples kind is very common in business and management (Bryman 1989a: 113-14 cited by Bryman & Bell, 2003, p. 105) Sample Design The aim of the sample was for me to select estimated population parameters. I planned getting a sample size of 300 from the population and from the service sectors so that I could be sure with a large sample. I planned to get 100 customers from each organization. By the end of the collection of data, I got 100 completed and 7 uncompleted questionnaires from international students of Umeå University; 60 completed questionnaires from customers from ICA Ålidhem and 60 completed questionnaires from customers from Forex. Source: (Agbor, 2011) A B Question Answer A. What was the sample in the research example? B. What were the important characteristics of the sample? C. What was the sampling method used? D. What was the sampling technique used? E. Why was that sampling technique used? What I Have Learned 1. The ________ is a representative portion of the population. Before the study begins, the sample size had been planned beforehand and the systematic manner of selecting the elements that will make up the sample. 2. The sample is good if it is both accurate and precise based on the __________. 3. _________ is the process of selecting the elements that make up the sample coming from the population. Sampling methods could be random (probability sampling) or nonrandom (nonprobability sampling). 4. Probability sampling makes use of the following techniques: _________, ________, ________, ________ and multistage sampling. 5. Nonprobability sampling uses the following techniques: accidental, ________, purposive, ________ and ________ sampling. 6. One way of determining the sample size is using Slovin’s formula. Otherwise the researcher could base his sampling design from relevant Related Studies. 6 What I Can Do Complete the table below. Column A is a list of research problems. Determine the possible sampling method in Column B. In Column C, determine the possible sampling technique based on the sampling methods in Column B. Give your reason for the sampling technique in Column D. A B C D Research Problem Sampling Sampling Reason method technique Example: How do parents feel Nonrandom Purposive The parents of senior about the K to 12 program high school are the ones implementation? affected most. 1. What is the antimicrobial effect of Cissus sicyoides (Princess Vine) Adventitious Root Ethanolic Extract on Escheria coli and Aspergillus niger? 2. What are the effects of online marketing on the sales of small and medium enterprises? 3. What are the factors affecting the career preferences of Grade 12 senior high school students of XYZ Senior High School? Assessment Completion Test. Carefully read and understand the given situations below. On a separate answer sheet, copy and complete the tables below. A. Given a population of 2,000 mall shoppers, compute the sample size using Slovin’s formula. Margin of error (e) Sample size (n) 1% (1) 2% (2) 3% (3) B. A group of Grade 12 ABM students would like to determine the students’ satisfaction level of DEF High School on their school’s canteen services. The population of 2,000 students are made up of: Grade Level Population (N) Sample size (n) 7 525 (4) 8 500 (5) 9 500 (6) 10 475 (7) TOTAL N = 2000 N = 200 7 Using stratified sampling technique, determine the number of student participants from each grade level based on the sample size of 200. Additional Activities Directions: With the proposed quantitative research problem in mind (aligned with your strand i.e. ABM, HUMSS, STEM, etc). Analyze your new research problem and answer the question below to complete the table. Possible Title for your Practical Research 2 study: A B Question Answer A. What will the sample be in your proposed study? B. What are the important characteristics of the sample? C. What will be the sample size? How will you determine the sample size? D. What sampling method will you use? E. What sampling technique will you use? F. What is your reason for choosing that sampling technique? 8