Define the validity and reliability of test. Further explain their relationship.
ASSIGNMENT No. 2
- No. 1 Define the validity and reliability of test. Further explain their relationship.
Reliability is the extent to which test scores are consistent, with respect to one or more sources of inconsistency—the selection of specific questions, the selection of raters, the day and time of testing.
Reliability refers to how dependably or consistently a test measures a characteristic. If a person takes the test again, will he or she get a similar test score, or a much different score? A test that yields similar scores for a person who repeats the test is said to measure a characteristic reliably.
How do we account for an individual who does not get exactly the same test score every time he or she takes the test? Some possible reasons are the following:
Test taker’s temporary psychological or physical state. Test performance can be influenced by a person’s psychological or physical state at the time of testing. For example, differing levels of anxiety, fatigue, or motivation may affect the applicant’s test results.
Environmental factors. Differences in the testing environment, such as room temperature, lighting, noise, or even the test administrator, can influence an individual’s test performance.
Test form. Many tests have more than one version or form. Items differ on each form, but each form is supposed to measure the same thing. Different forms of a test are known as parallel forms or alternate forms. These forms are designed to have similar measurement characteristics, but they contain different items. Because the forms are not exactly the same, a test taker might do better on one form than on another.
Multiple raters. In certain tests, scoring is determined by a rater’s judgments of the test taker’s performance or responses. Differences in training, experience, and frame of reference among raters can produce different test scores for the test These factors are sources of chance or random measurement error in the assessment process. If there were no random errors of measurement, the individual would get the same test score, the individual’s “true” score, each time. The degree to which test scores are unaffected by measurement errors is an indication of the reliability of the test.
Reliable assessment tools produce dependable, repeatable, and consistent information about people. In order to meaningfully interpret test scores and make useful employment or career-related decisions, you need reliable tools. This brings us to the next principle of assessmen
- No. 2 Develop a scoring criteria for essay type test items for sixth grade.
Essay test is a test containing questions that requires the examinee to write several paragraphs in their own words. Generally, essay tests are designed to measure the different abilities of examinees such as factual knowledge, language proficiency with legible handwriting, organizing answer and time management.
Introduction to Essay Test:
The essay tests are still commonly used tools of evaluation, despite the increasingly wider applicability of the short answer and objective type questions.
There are certain outcomes of learning (e.g., organising, summarising, integrating ideas and expressing in one’s own way) which cannot be satisfactorily measured through objective type tests. The importance of essay tests lies in the measurement of such instructional outcomes.
An essay test may give full freedom to the students to write any number of pages. The required response may vary in length. An essay type question requires the pupil to plan his own answer and to explain it in his own words. The pupil exercises considerable freedom to select, organise and present his ideas. Essay type tests provide a better indication of pupil’s real achievement in learning. The answers provide a clue to nature and quality of the pupil’s thought process.
That is, we can assess how the pupil presents his ideas (whether his manner of presentation is coherent, logical and systematic) and how he concludes. In other words, the answer of the pupil reveals the structure, dynamics and functioning of pupil’s mental life.
The essay questions are generally thought to be the traditional type of questions which demand lengthy answers. They are not amenable to objective scoring as they give scope for halo-effect, inter-examiner variability and intra-examiner variability in scoring.
- No. 3 Write a note on scales of measurement.
Scales of Measurement
In Statistics, the variables or numbers are defined and categorised using different scales of measurements. Each level of measurement scale has specific properties that determine the various use of statistical analysis. In this article, we will learn four types of scales such as nominal, ordinal, interval and ratio scale.
What is the Scale?
A scale is a device or an object used to measure or quantify any event or another object.
Levels of Measurements
There are four different scales of measurement. The data can be defined as being one of the four scales. The four types of scales are:
- Nominal Scale
- Ordinal Scale
- Interval Scale
- No. 4 What are the advantages and disadvantages of norm-reference testing?
A norm-referenced test (NRT) is a type of test, assessment, or evaluation which yields an estimate of the position of the tested individual in a predefined population, with respect to the trait being measured. Assigning scores on such tests may be described as relative grading, marking on a curve (BrE) or grading on a curve (AmE, CanE) (also referred to as curved grading, bell curving, or using grading curves). It is a method of assigning grades to the students in a class in such a way as to obtain or approach a pre-specified distribution of these grades having a specific mean and derivation properties, such as a normal distribution (also called Gaussian distribution).The term “curve” refers to the bell curve, the graphical representation of the probability density of the normal distribution, but this method can be used to achieve any desired distribution of the grades – for example, a uniform distribution. The estimate is derived from the analysis of test scores and possibly other relevant data from a sample drawn from the population. That is, this type of test identifies whether the test taker performed better or worse than other test takers, not whether the test taker knows either more or less material than is necessary for a given purpose. The term normative assessment is used when the reference population are the peers of the test taker.
Norm-referenced assessment can be contrasted with criterion-referenced assessment and ipsative assessment. In a criterion-referenced assessment, the score shows whether or not test takers performed well or poorly on a given task, not how that compares to other test takers; in an ipsative system, test takers are compared to previous performance. Each method can be used to grade the same test paper
- No. 5 What are the different graphical techniques to display the results of students? Write in detail.
Graphical representation refers to the use of intuitive charts to visualise clearly and simplify data sets. Data obtained from surveying is ingested into a graphical representation of data software. Then it is represented by some symbols, such as lines on a line graph, bars on a bar chart, or slices of a pie chart. In this way, users can achieve much more clarity and understanding than by numerical study alone.
Advantages of Graphical Representation
Some of the advantages of using graphs are listed below:
The graph helps us understand the data or information even when we have no idea about it.
It saves time.
It makes it easier for us to compare the data for different time periods or different kinds.
It is mainly used in statistics to determine the mean, median and mode for different data and interpolation and extrapolation of data.
Use of Graphical Representations
The main agenda of presenting scientific data into graphs is to provide information efficiently to utilise the power of visual display while avoiding confusion or deception. This is important in communicating our findings to others and our understanding and analysis of the data.
Graphical data representation is crucial in understanding and identifying trends and patterns in the ever-increasing data flow. Graphical representation helps in quick analysis of large quantities and can support making predictions and informed decisions.
General Rules for Graphical Representation of Data
The following are a few rules to present the information in the graphical representation:
Suitable title: The title of the graph should be appropriate that indicates the subject of the presentation.
Measurement unit: The measurement unit in the graph should be mentioned.
Proper scale: Choose a proper scale to represent the data accurately.
Index: For better understanding, index the appropriate colours, shades, lines, and designs in the graphs.
Data sources: Data should be included wherever it is necessary at the bottom of the graph.
Keep it simple: The construction of a graph should be such a way that it is effortlessly understood.
Neat: The correct size, fonts, colours etc., should be chosen so that the graph should be a visual aid for presenting the information.
Types of Graphical Representation
- Line graph
3. Bar graph
4. Pie chart
5. Frequency polygon
6. Ogives or Cumulative frequency graphs