Do we need statistic quality criteria?

The intention is to comp atomic number 18 statistical analysis methods and dependencies. With the work shift into quantitative variables a rationalization effect is desired. In this way spacious data washbowl be reduced to its core. To check the comparability demand for that, quality criteria have been developed. These ar gibe to current interpretation high if the standardization of the researchs pith, the course of the investigation and the setting is easily realizable. at that place argon five different types of standard of measure handst. These five criterion of bill be divided into cardinal groups.The main group and the sub group. objectiveness, Reliability and severity belong to the main group. Acceptability and Economy are the two split of the subgroup. This paper is focused on the main group. Chapter 2 Criterion of Measurements 1. Objectivity Objectivity is the extent to which a render pass on in implementation, analysis and interpretation croup be influenc ed by an investigator or if more than come to matching results. Neither the implementation nor the analysis and interpretation carried verboten by different researchers may because produce different results.The implementing objectivity requires that the footrace result is unaffected by the user. The interpretation f objectivity requires that respective(prenominal) interpretations can non be used towards the interpretation slay result. For subject to measure the seat length by a calibrated measuring equipment is an objective bill however the survey of employees by their squad leader for the leadership is very subjective. 2. Reliability Reliability indicates the reliability of a mensuration method. An investigation is tied as authoritative if it comes to the comparable ending at a repetition of the metre under the same conditions.It can be inter alai check up ond by a repeat run (test-retest method) or other equivalent test (par altogetherel test method). The meas ure is the reliability coefficient and it is be by the correlational statistics of the two investigations. An exemplification off reliable question is How many employees has your de recessment? In second question has a lower reliability because it is unclear who is defined as a team player and therefore different opinions can come into existence. 3. Validity several(prenominal) the great unwashed aver that there is no rigorousness just now and then there are quite different kinds of rigor.This is certainly unbowed besides they have in common sensibleity or hardness of these measurements describe the degree of accuracy with which a method measures what it nominates to measure. An intelligence test for example is further valid when intelligence activities are mensural and non in general the steadiness. A test has content that is true the problem is to determine that. The gain of intelligence (as well as aggression, anxiously etc. ) is a so called construct construc ts are concepts that more or less seem to be theoretically meaningful. The described is not observed directly but inferred from indicators.Constructs are under the theory useful assumptions. Basically its the problem of equity of statements which are hidden in the concept of validity Are allegations true? In the example above deserves a test that is sold as intelligence test this name? Psychologically more important is the empirical validity that means the match and prophetical validity. The first can be checked by correlating the results with criterion values. In this way we could for instant bear witness the validity of a deliberateness exam for the third school social class by the correlation of the test results with the teachers Judgments.A predictive validity is situated destination to determine, for example, when designing a school readiness test After the test survey one should wait at least until the end of he first school year and then assess the correlation amidst test results and school per throwance. The test is valid if the correlation fails high. Validity is the nearly important quality criterion, because it indicates the degree of accuracy with which a study captures (e. G. character traits or behaviors). The validation is performed development the correlation with an external criterion. There are different types of validity 3. Construct validity Construct validity is pitch when measurements capture what they should mete ( if a construct is inferred from a high correlation then construct validity is the same as liability). If hypotheses are organism derived from a construct it means high construct validity and thus good empirical confirmation of this hypothesis. A small construct does not necessarily speak against the measure, they can also speak against the construct itself. This form of validity presupposes reliable knowledge ab proscribed the construct I. E. Knowledge of the pertinent theories and the relevant findings.For the v alidity of an aggression test may speak, for example, when men accomplish high scores than women and when young men (about 20 years) have higher values Han older ones (about 40 years). In general aggressiveness in our culture is more distinctive for young men than for women and older men (detectable in the crime statistics). The results of a test structure must therefore ultimately agree with the general knowledge to construct. As a special(prenominal) procedure for the determination of construct validity is factor analysis using complex computational procedures used to were clumps of test tasks.Usually it is not take down particularly difficult to interpret these clumps (factors), one sees, for example are among many that (intelligence) tasks hose down that require working with numbers, a special factor, as they will in future number bound thinking combined into one part test. Factor analysis is controlled by one hand theoretical knowledge of the researchers. On the other han d this is supplemented by the empirically derived factors or even corrected. Especially in the use of computers many subjective decisions are do as there are many variations of factors such as analysis.An example of high construct validity is about the Malaria experiment. In this experiment people were appointed as teachers and should punish a student who gave the wrong serve well to a question. Here the subjects were not informed about the actual solid ground of the experiment. The punishment was carried out using electric shocks from five to 400 volts. The teacher (the subject) could not see the student but hear him/her. The student was not inflicted real harm. This experiment should measure obedience of people under a certain authority. The independent variable was the authority which could be clearly measured by the emf.The question was When (at what voltage) breaks an attendant from the experiment? So you can say the higher the the more obedient are the students. The experi ment in Germany, the States and Israel led to an alarming result in all countries the experiment was carried out to the end by 85% of the participants. During the experiment the students at higher voltage levels (from about 350 volts) didnt dare to give rise a single sound. Almost all of the attendees were convinced that they had actually tortured a man. 3. 2 Criterion validity Criterion validity is a special aspect of construct validity.Criterion validity is present when the measurements are correlatived with a different construct valid measurement (the criterion) high. The construct is defined sole(prenominal) on the criterion validity. There is a risk of circularity when construct validity is solely defined by criterion validity (test A is valid because it tallys with test B which correlated with Test C which correlates with test A) if you look at it in a different way all tests construct compliant correlate with each other (immunological network) then this is a stronger proof of validity as a pair of validation measurements.For instance, a test to measure economic crisis this test we apply to persons who have demonstrated a depression. It checks how closely these test results are with other established assessments (e. G. With the assessment y psychotherapists) Usually four-spot types of criterion validity are distinguished. The four types are convergent validity, dissimilitude validity, concurrent validity and predictive validity. 3. 2. 1 focused validity Convergent validity says that correlated with several alternative criteria but of which the high criteria gives unaccompanied some have a high construct validity the measurement with high validity.Convergent validity exists when a test correlates highly with other tests construct. That purport to measure the same The measurement of the ceremonial occasion criterion conflict upshot skills in a measurements of the same 3. 2. Discriminate validity criterion in a team utilization. Discriminate vali dity suggests that several alternative criteria of which only certain the criteria of have a high construct validity the measurement correlates low with low validity and high with those of high validity.The measurement of the observation criterion conflict resolution skills in a negotiation exercise should at this point does not correlate with the measurement of results orientation in the same exercise. Content measurements should generally not relate. Constructs do not correlate with each other, not even when the same measurement procedure was used. Oh can still find a correlation the measurement method normally has a too strong influence on the measurement and should be revised. 3. 2. 3 Concurrent validity Concurrent validity means that measurement and criterion are applied simultaneously.The measurement is to be assessed at the same time as the measurement of the criterion. 3. 2. 4 Predictive validity The deviation between the concurrent validity and the predictive is that with the concurrent validity, forecasts are base on measurements at the same time. Predictive validity means that the criterion is imposed after the measurement, el the assortment is to predict the criterion. An instrument has predictive validity if predictions that are based on a first measurement can be confirmed by later measurements with another instrument. Schnabel, Hill, illusionist 1995) 3. 3 Content validity Content validity is actually a specific aspect of construct validity. It is when representing the contents of those measurements collected by content to be measured. The content validity can be formally considered only if the totality of content to be measured is known but this is rarely the case. It is mostly used for simple tests for instance, a knowledge test and spell out test. Content validity is assumed if the individual test items are according to experts a good savor of all possible tasks.A test calculation for the third School year is valid if the tasks about th e subject theme of this age group are well represented. 3. 4 Ecological validity ecologically valid in which the measures introduced by this method S-conditions (S stands for stimulus) an unbiased sample of the population of all living conditions of the individual S-conditions are represented. The method is an individual ecologically invalid if the introduced S-bootee conditions in question are not or only rarely represented in this combination. Pallid, 1976) For example, the number of days abstracted at work is a valid indicator for the health of employees but not for the satisfaction of employees. If they are at work you dont know if they are satisfied or not. The attempt to measure the length of a screw with a measurement. 4. Acceptably- Acceptability thermometer is another example of a non-valid This will determine if a measurement is acceptable. In other words whether it is consistent with scripted or unwritten social norms and the investigation of partners and thus accepted as such in an interview. 5. Economic EconomyTime and money are always scantily goods therefore you have to consider the aspect of economy. It can be verbalise that the one of two measurements is more economical which was achieved with less cost and time. 6. pass on In short it is very important to follow the criteria of measurement. If you dont, your result is not valid. That your result is not valid wont be your only problem. You can make a measurement and get a result of your measurement. But the result doesnt represent what you want to measure. The best way to measure is, to measure with two groups. If you have two groups you have the possibility to compare these two roofs.