Techniques of Analyzing the Data

F. Techniques of Analyzing the Data

1. The Instrument of Examining

a. Validity

Before the researcher provides the test for the students, the researcher goes to validate the test to validators in order to know the validation of the test. According to Ary, et al (2002:227) “Validity concerns to the extent to which the scale really measure the attitude constru ct”. It means, the test is valid if the test really measures the stu dents’ ability of what they have learnt in advance. If the Before the researcher provides the test for the students, the researcher goes to validate the test to validators in order to know the validation of the test. According to Ary, et al (2002:227) “Validity concerns to the extent to which the scale really measure the attitude constru ct”. It means, the test is valid if the test really measures the stu dents’ ability of what they have learnt in advance. If the

To know the validity of the test, the researcher uses internal validity (Rational Validity). It is determined by expert j udgment. The researcher gives the sheet of instrument validity test (See Appendix 5) to the qualified teachers validate the test.

For more clearly, the ways to fill the sheet of instrument validity test as follows:

a) The qualified teachers or lecturer determine “Yes” or “No” whether the test is composed based on the kinds of hoped prerequisite.

b) The qualified teachers or lecturer determine scoring scale for each of prerequisite based on the composing of test.

c) The qualified teachers or lecturer determine the test is valid, valid enough, less valid, or not valid based on the result of their analysis about the test in point a) and b) above. If: Valid

= 4, means the item can be used without any revision Valid enough = 3, means the item can be used with less revision Less valid

= 2, means the item can be used, need a consultation Not valid

= 1, means the item cannot be used.

b. Reliability

Last, J. (Ed.). (2001:125) says, a common threat to internal validity is reliability. Assuming the same initial conditions for a test assessment or process the test must provide the same result every time it is performed for it to be deemed reliable.

2. The Data Analysis

a. The Students’ Ability in Writing Narrative

To evaluate th e result of the students’ writing in skill, the researcher uses the formula according to Alaska (2007:24), see on page 24. To gain the students’ mark in writing narrative text

Obtained Score

Students’ Mark = X 100

Maximum Score

After getting the students’ mark, the researcher decides the whole percentage of the students’ ability by using the formula as Tuckman in Nurgiantoro (1986: 345 – 347) formulates:

Which: TP

: The Degree of Percentage FB : The Stu dents’ Value

N : The Amount of The Students

The criteria of the study of students’ ability are:

86 – 100 = Very good

b. Normality

Examining the normality is used to find out whether the sample comes from the normal distribution in order that the sample can represent the population and it is used for all the equal population. To examine the normality, the researcher uses Liliefors formula defined by Sudjana (2002:466-477) by following some steps, as follows:

1) Calculate the standard value (Zi) with this formula:

2) Determine the broad under the standard of normal curve from 0 to z in the

table.

3) Determine F(Zi) by following this rule:

a) For the (Zi) signed negative F(Zi) = 0.5 – the broad under the standard of normal curve from 0 to z

b) For the (Zi) signed positive F(Zi) = 0.5 + the broad under the standard of normal curve from 0 to z

4) Determine S(z) with this formula:

5) Determine the absolute value from F(Zi) – S(Zi)

6) Determine the highest absolute value from F(Zi) – S(Zi) as Lo

7) Determine L table by using the table of critical value L for Liliefors test = L α(n)

8) Draw a conclusion by following these rules below:

a) If Lo ≤ L table , the sample has the normal distribution.

b) If Lo ≥ L table, the sample doesn’t have the normal distribution.

Table 4

THE WORK TABLE for LILIEFORS FORMULA

x- x

Zi F(Zi) S(Zi) F(Zi) – S(Zi)

L count = Lo

L table =L α(n)

Conclusions

c. Homogeneity of the Sample

To find the homogeneity of the sample, the researcher uses the formula of Harley Test. Irianto (2007:276) states that test the homogeneity variant by Harley can be used if the total of sample both group is equal. The Formula is:

1) Determine the highest variants and the lowest variants.

2) Seek F count by using this formula:

F count =

3) Determine F table by using this formula:

F table =F α ( n the highest variants – 1, n the lowest variants – 1) by using F table is gotten

F table.

4) Determine the conclusion with criteria: (a) If Fcount ≤ Ftable, Ho is accepted (homogenous) (b) If Fcount > Ftable, Ho is unaccepted (heterogeneous)

d. Mean

To see the mean of the data, the researcher uses formula as Sudjana (2002:70) formulates:

Which:

X = The Mean of Variable X

f i = The Frequency of Data Score X Xi = The Score of Center Point of Interval n = The Sum of Data

e. Standard Deviation

To see the standard deviation of the data, so it is counted by using formula of Sudjana (2002:95) as below:

Which: S

= Standard Deviation of Variable X Xi

= The Score of Center Point Interval

f i = The Frequency of Data Score n

= The Number of the students

f. Examining Hypothesis

Examining hypothesis, the researcher uses the formula by Arikunto (2001:95) as in the next page:

S=

Which:

t count = Amount of t count

X 1 = The Mean of Experimental Group

X 2 = The Mean of Control Group

n 1 = Total of Experimental Group

n 2 = Total of Control Group

1 = The Variants of Experimental Group S 2

2 = The Variants of Control Group

S = The Unity of Standard Deviation

The formulation of hypothesis which is examined by t-independent test, namely: Ho

: Ha :

So, criterion of examining hypothesis by using t- independent test is “Ho is accepted and Ha is refused if

(dk) –t or refusing Ho and ⁄ t ⁄ accepting Ha for vice versa.”

(dk)