56 Table 10. The Result of Reliability Instruments
No Variable Instruments
Alpha Cronbach
Coefficient Reliability
Description
1 Locus of Control X1
0,615 Strong
2 Students
Perceptions of
Teacher Teaching Methods X2
0,820 Very Strong
3 Parents Concern X3
0,879 Very Strong
Source. The primary data source has processed
I. Data Analysis Techniques
1. Data Description
The data obtained from the field, would be presented in the form of a data description of each variable, both independent and the dependent
variables. The Analysis of the data description should include the presentation of Mean M, Median Me, Modus Mo, and Standard
Deviation SD, Frequency Distribution Tables, Graphs and Table Category tendency of each variable.
a. Mean Mean is the arithmetic average of the data or a typical value that can
represent a set of data. The formula uses:
Descriptions: Me
= Mean ∑fi
= Total of data fiXi
= Multiple between f
i
each interval with class Xi. Sugiyono, 2012: 54
57 b. Median is a central value data when the values of the data that are
arranged in order according to the amount of data. The formula uses :
[ ]
Descriptions: Md
= Median b
= Under line n
= Total of data p
= Interval class length F
= Total of frequency before median class F
= frequency of class median Sugiyono, 2012: 53
c. Modus is the value of the data most frequently occurs or data value with the greatest frequency. The formula uses:
Descriptions: Mo
= Modus b
= interval class line with the most frequency p
= interval class length b1
= frequency in class modus subtraction the nearest interval Class
b2 = frequency in class modus subtraction the next interval
class Sugiyono, 2012: 56
d. Standard deviation is a measure of the spread of data since it has a set of data and a middle value.
�
= √
Descriptions: �
= deviasi standard n
= total of data x1-x
= simpangan
58 e. The frequency distribution table
1 Determine the number of class intervals To determine the length of the interval, use the formula Sturges
Rule,is: k=1+3,3 log n
Descriptions: k = total of data class
n = total of observation data log = logaritma
Sugiyono, 2015: 35 2 Determine a range
To determine a range, use this formula, as follow : Range = score maximum
– score minimum 3 Determine a long class
To determine a long class, it uses this formula, as follow :
4 Histogram The Histogram is made depending on frequency data which show
on the frequency distribution table. 5 Variable tendency table
The next step is to determine the categorization score, which is obtained by each variable. From the score, it will be
divided into 4 categories. Categorizing implemented by Mean and SD obtained.
59 a TopHigh
All respondents who had the score as much as the mean plus 1 deviation standard to top M + 1 SD
b MiddleEnough All respondents who had a score between mean score
minus 1 standard deviation and mean score plus 1 standard deviation
Between M – 1SD till M + SD
c UnderLow All respondents who had a score lower than the mean
score minus 1 standard deviation M – SD
Table 11. Data Research Variables are Categorized by the Following Rules:
Scale Catagories
M + 1SD High
Mi – 1SD till M + 1SD
Enough M
– 1SD Low
Anas Sudjiono, 2014: 176 6 Pie chart
Pie chart is made depending on tendency data that have showed on variable tendency table.
60
2. Prerequisite Test Analysis
