TOU 028 - Research in Tourism P1 PDF

TOU 028 - RESEARCH IN TOURISM P1 Data at this level do not have a natural zero starting point at which none of the quantity is present. STATISTICS BRANCHES, PARAMETRIC V...

TOU 028 - RESEARCH IN TOURISM P1 Data at this level do not have a natural zero starting point at which none of the quantity is present. STATISTICS BRANCHES, PARAMETRIC VS NON-PARAMETRIC, LEVELS OF MEASUREMENT, SAMPLING Data are at the ratio level of measurement - can be arranged in order, differences can be found and meaningful, and there is a natural zero starting STATISTICS point (zero indicates that none of the quantity is present). For data at this The science of planning studies and experiments, obtaining data, organizing, level, differences and ratios are both meaningful. summarizing, presenting, analyzing, and interpreting those data, and then drawing. SAMPLING The process of selecting certain members or a subset of the population to BRANCHES OF STATISTICS make statistical inferences from them and to estimate characteristics of the Descriptive statistics deals with data collection and presentation and is whole population devoted mainly to the summarization and description of data sets. Inferential statistics involves making inferences and drawing the correct TYPES OF SAMPLING conclusions; used when one makes a decision, estimates a prediction, or Probability sampling is also known as random sampling or chance sampling; makes generalizations about a population based on a sample. the sample is taken in such a manner that each and every unit of the population has an equal and positive chance of being selected. PARAMETRIC VS NON-PARAMETRIC Parametric tests – are tests applied to data that are normally distributed, the Non-probability sampling is any sampling method where some elements of levels of measurement of which are expressed in interval and ratio; have the population have no chance of selection (these are sometimes referred to requirements about the distribution of the populations involved; a test of as ‘out of coverage'/'under covered’), or where the probability of selection significance and relationship appropriate when the data represent an interval can’t be accurately determined. Does not allow the estimation of sampling or ratio scale of measurement and other assumptions have been met. errors. Non-parametric tests - are tests that do not require a normal distribution and PROBABILITY SAMPLING utilize both nominal and ordinal data; a test of significance appropriate when 1. SIMPLE RANDOM SAMPLE the data represent an ordinal or nominal scale when a parametric assumption A simple random sample of n subjects is selected in such a way that every has significantly been violated; does not require that samples come from possible sample of the same size n has the same chance of being chosen. populations with normal distributions or any particular distributions. Advantage: the sample will be free from bias. Disadvantage: difficult to obtain; due to its very randomness, “freak” results can sometimes be obtained that LEVELS OF MEASUREMENT are not representative of the population. The nominal level of measurement - consist of names, labels, or categories only. The data cannot be arranged in some order (such as low to high). 2. SYSTEMATIC RANDOM SAMPLE Requires numbering the entire population; easier and more likely to represent Data are at the ordinal level of measurement - can be arranged in some different subgroups; every nth number (say every 5th or 10th number, as the order, but differences (obtained by subtraction) between data values either case may be) is selected to constitute the sample. Advantage: can eliminate cannot be determined or are meaningless. other sources of bias. Disadvantage: it can introduce bias where the pattern used for the samples coincides with the pattern in the population. Data are at the interval level of measurement - can be arranged in order, and differences between data values can be found and are meaningful. 3. STRATIFIED SAMPLING The population is first divided into groups or strata, each of which is homogeneous with respect to the given characteristic feature; then, samples are drawn at random from each stratum. Advantage: yields more accurate ​ Chain sampling results than simple random sampling and can show different tendencies within ​ Criterion sampling each category. Disadvantage: nothing major; hence it is used. 4. SNOWBALL SAMPLING N = N = 2900 = 352 1 + NE2 1 + 2900 A method in which a researcher identifies one member of some population of (.05)2 interest, speaks to him/her and then asks that person to identify others in the population that the researcher might speak to. This person is then asked to 4. CLUSTER/ MULTISTAGE SAMPLING refer the researcher to yet another person, and so on Used against The selection of units may pass through various stages before you finally low-incidence or rare populations reach your study sample. Includes a combination of random, stratified, and cluster sampling at different stages. SOME OTHER SAMPLING METHODS Advantage: less expensive and time-consuming than a fully random Matched random sampling - method of assigning participants to groups in sampling; can show regional variations. which pairs of participants are first matched on some characteristic and then Disadvantage: not a genuine random sampling; likely to yield a biased result individually assigned randomly to groups (especially if only a few clusters are sampled) Mechanical sampling - typically used in sampling solids, liquids, and gases, using devices such as grabs, scoops; thief probes, etc. NON-PROBABILITY SAMPLING Line-intercept sampling - a method of sampling elements in a region 1. ACCIDENTAL/ CONVENIENCE SAMPLING whereby an element is sampled if a chosen line segment, called a ‘transect’, Involves the sample being drawn from that part of the population that is close intersects the element at hand A sample population is selected because it is readily available and Panel sampling - the method of first selecting a group of participants through convenient Most useful for pilot testing a random sampling method and then asking that group for the same information again several times over a period of time 2. QUOTA SAMPLING Rank sampling - a non-probability sample is drawn and ranked. The highest The population is first segmented into mutually exclusive sub-groups, just as value is chosen as the first value of the targeted sample in stratified sampling. Judgment is used to select the subjects or units from each segment based on a specified proportion The selection of the sample is SO, WHAT STATISTICAL TOOL ARE YOU GOING TO USE IN YOUR non-random STUDY? 3. SUBJECTIVE, OR PURPOSIVE, OR JUDGMENT SAMPLING The sample is selected with a definite purpose in view The choice of the sampling units depends entirely on the discretion and judgment of the investigator Sampling suffers from drawbacks of favoritism and nepotism Seldom used and cannot be recommended for general use since it is often biased due to element of subjectivity on the part of the investigator NON-PROBABILITY SAMPLING SOME PURPOSIVE SAMPLING STRATEGIES THAT CAN BE USED IN QUALITATIVE STUDIES ARE: ​ Extreme case sampling ​ Maximum variation sampling ​ Homogeneous sampling ​ Typical case sampling ​ Critical case sampling