TASK NO: 1 WHAT DO SYMBOLS IN STATISTICAL FORMULA MEAN?

1.    Identify and define Statistical symbols.

statistic	When to use	What it means
R	To measure how strong relationship between two variables	Sample Correlation Coefficient
r 2	To explained how much variability of one factor can be caused by its relationship to another factor	Correlation of Determination
R2	In regression analysis to assess quality of prediction of dependent variable.	Multiple correlation coefficient
Yʹ	Variable that is being measured or tested in an experiment.	Dependent variable
b	To calculate regression line	Slope of regression line
X	Used to perform statistical analysis	Raw score
P	When to associate certain parameter of population or to determine outcome of event	Population portion or probability
Df	To find critical cutoff values for inferential statistical test	Degree of freedom

 TASK NO:2 HOW DO I INTERPRET CORRELATION COEFFICIENT

1.    Determine whether correlation coefficient are significant

	N	Tail	Validity coefficient	Alpha Set	Df=n-2	Critical Value	Is the correlation significant	Rationale
1	47	One	.3814	.05	45	1.684	Significant correlation	Alpha value .05 shows significant correlation
2	72	One	.2959	.05	70	1.671	Significant correlation	Alpha value .05 shows significant correlation
3	16	One	.5104	.005	14	2.977	Not significant	Alpha value .005 do not show significant correlation
4	92	One	.2627	.01	90	2.390	Significant correlation	Alpha value .01 shows significant correlation
5	27	One	.3417	.005	25	2.787	Not significant	Alpha value .005 do not show significant correlation
6	42	One	.5176	.025	40	2.021	Not significant	Alpha value .025 do not show significant correlation
7	15	One	.5417	.05	13	1.771	Significant correlation	Alpha value .05 shows significant correlation
8	38	One	.2897	.05	36	1.697	Significant correlation	Alpha value .05 shows significant correlation
9	102	One	.2714	.01	100	2.358	Significant correlation	Alpha value .01 shows significant correlation
10	32	One	.2798	.05	30	1.697	Significant correlation	Alpha value .05 shows significant correlation

2.    Answer the question below.

 Why are the test of significance important when examining evidence of validity?

Test significance is important when examining evidence of validity because it will determine either correlation is significant or not based on the alpha value.

 

What happens when a small change in the critical value or degree of freedom is made and how could the changes effect the data and result?

When the changes made in critical value or degree of freedom even small one can effect the acceptance or rejection of null hypothesis or finding significant results. If increase in critical value than the test statistics result will not significant and accept the null hypothesis. Same in increase of degree of freedom increase the sample size and give more power to reject false null hypothesis and significant result.

 

What would happen if changed you the alpha level? How would the change effect the validity of the test based on the test-criterion relationship?

The change in alpha will also affect the Type II error, in the opposite direction. Decreasing alpha from 0.05 to 0.01 increases the chance of a Type II error (makes it harder to reject the null hypothesis).  In test-criterion relationship one measure compare with predetermined criterion test changes in one’s alpha level will affect the relationship negatively and not measure what it was exactly intended to mean,

Task no:3 what is the relationship between reliability and validity

1.    Define key terms to describe relationship between reliability and validity

Term	Five to seven  words definition	Why is the term important to understand in the context of psychological testing?
True score	Individual score without error on test	In scoring of the test this term is commonly use
Attenuation due to unreliability	Correlation between unreliable measures	In reliability correlation this term is widely use
Reliability coefficient	Applying test more than once to check accuracy	In reliability correlation this term is widely use
Validity coefficient	Usefulness of a test to predict	To understand the concept of validity its is important because commonly use
Operational validity	Estimate relationship between predictor and criterion construct	To understand the concept of validity its is important because commonly use
Predictor construct	Behavior domain being sampled	To understand the concept of construct validity its is important because commonly use
Construct	A label for a domain of behaviors	To understand the concept of construct validity its is important because commonly use
Criterion measure	Comparison of measure with predetermined measure	In criterion referenced test this term is used.
Random error	Factors effect the variables or process of measurement	In psychological experiments And sampling this term is used.
Observed measures	Measure that can be observed	In psychological experiments And sampling this term is used.
Predictive validity	Test predicts scores on some criterion measure	To understand the concept of types of validity it is important because commonly use
Observed validity coefficient	Correlation between test score and criterion variables	To understand the concept of validity its is important because commonly use
Measurement error	Difference between measured quantity and true score	In developing psychological tests this term is commonly used
Observed criterion measure	Predetermined measure that can be observable	In developing psychological tests this term is commonly used
Correction of attenuation	Method to estimate relationship between two constructs	In order to understand correlation this term is used.
Relationship	Way of correlating two or more things	In order to understand correlation this term is used.
Criterion construct	Conceptual predetermined measure	In psychological experiments And sampling this term is used.

TASK NO: 4 REFLECT ON YOUR LEARNING

1.    Identify your “Aha” moments.

INSIGHT AND REALIZATIONS:  

Ø  In this chapter 7 I have come to know about the basic concepts used in psychological testing like validity, reliability their types and calculations.

Ø  I have learned the statistical calculations for psychological testing critical value, test of significance, hypothesis testing, alpha values, validity check, reliability check, correlation coefficient that I never know before in detail

Ø  I have also learned the different statistical terms and formulas that are applicable to the different practical things in our daily life.

2.     Identify some muddy moment discussion question.

Discussion questions:

Ø  Examples of calculation of hypothesis testing by using different conditions and formulas with given values.

Ø  How to test validity? And find evidence for validity?