Analisis data upload 1 0

ANALISIS DATA
SMT 310
retnosubekti@uny.ac.id

Motivasi






Memahami analisis eksplorasi dan
konfirmasi
Landasan statistika deskriptif dan
inferensi
Bersinergi dengan komputasi statistik
untuk meng-upgrade kemampuan
analisis data

Deskripsi











Penyusunan dan rangkuman data
numerik
Penyajian data univariat
Transformasi data
Sampel acak
Statistika konfirmasi
Analisis variansi
Hubungan antara dua variabel
Analisis data kategorik

Referensi





Erickson, Bonnie H & Nosanchuk. 1987.
Memahami Data : Statistika untuk Ilmu
Sosial. (terjemahan RK. Sembiring &
Manase Malo). Jakarta: LP3ES
Griffiths D., Stirling W.D, Weldon K.L .
1998. Understanding Data : Principles
and Practice of Statistics. Brisbane : John
Willey & Sons

Kontrak








Penilaian
Bobot :
Tugas : 20%
Kuis
: 15%
Usip : 25%
Uas
: 40%

REVIEW










STATISTIKA ?
STATISTIK ?
STATISTIKA DESKRIPTIF ?
Statistika inferensi
Populasi
Sampel
Parameter
Statistik

Data




Nilai ujian metode stastistik 20 orang
mahasiswa adalah :
91

50


73

74

55

86

70

43

47

80

40

85


64

61

58

95

52

67

83

92

Misalkan diketahui nilai ujian komputasi
statistika 50 mahasiswa
44,7 59,8 67,1 57,1
48,4 63,9 67,8 56,2

42,5 57,2 70,2

57

49,1 64,7 74,6 63,6
43,1 76,5 68,7 59,9

58,2 69,5 60,6 44,2
60 68,2 48,5
62,2 70,3
63,5 72,6

46 72,6

50 76,8

63 72,2 75,3

76 51,2
52


74 65,1

75 55,4 67,7

77 73,5 56,3 77,3



Banyaknya penjualan HP di suatu toko :

Merek
HP
Nokia
SE
Samsun
g
LG
Lain


Penjualan
56
45
32
22
45

Skala pengukuran
Nominal :
 Ordinal:
 Interval
:
 Rasio
:
Contoh:
 Nominal: jenis pekerjaan, warna
 Ordinal: kepangkatan, tingkat pendidikan
 Interval: tahun kalender (Masehi, Hijriyah),
temperatur
 (Celcius, Fahrenheit)

 Rasio: berat, panjang, isi


Statistika deskriptif


Metode atau cara-cara yang digunakan
untuk meringkas dan menyajikan data
dalam bentuk tabel, grafik atau
ringkasan numerik data.

Grafik Stem-and-leaf



Untuk menunjukkan bentuk distribusi data
Data berupa angka dengan minimal dua digit

Contoh (Data penghasilan buruh):
439

511555689
602334445556777889
7122344558
8349
92
Stem= 10, Leaf = 1



Intro…

Why study statistics?
Make decision without complete
informations
Understanding population, sample
Parameter, statistic
Descriptive and inferential statistics

glossary
A population is the collection of all items of interest
or under investigation
N represents the population size
A sample is an observed subset of the population
n represents the sample size
A parameter is a specific characteristic of a
population
Mean, Variance, Standard Deviation, Proportion, etc.

A statistic is a specific characteristic of a sample
Mean, Variance, Standard Deviation, Proportion, etc.

Population vs. Sample
Population

Sample

      a  b     c d 
ef   gh i  jk l   m  n

       b     c  

  o  p q   rs  t  u v  w

     g i         n

      x   y      z

  o      r     u
         y      

Values calculated using 
population data are called 
parameters

Values computed from sample 
data are called statistics

Examples of Populations
Incomes of all families living in yogyakarta
All women with pregnancy problem.
Grade point averages of all the students in
your university


Random sampling
Simple random sampling is a procedure in which

each member of the population is chosen
strictly by chance,
each member of the population is equally
likely to be chosen, and
every possible sample of n objects is equally
likely to be chosen
The resulting sample is called a random sample

Descriptive and Inferential Statistics
Two branches of statistics:
Descriptive statistics
Collecting, summarizing, and processing
data to transform data into information

Inferential statistics
Provide the bases for predictions, forecasts,
and estimates that are used to transform
information into knowledge and decision

Descriptive Statistics
Collect data
e.g., Survey

Present data
e.g., Tables and graphs

Summarize data
e.g., Sample mean =

�X
n

i

Inferential Statistics
Estimation
e.g., Estimate the population
mean weight using the
sample mean weight
Hypothesis testing
e.g., Test the claim that the
population mean weight is
120 pounds

Inference is the process of drawing conclusions or making decisions about a 
population based on sample results

The Decision Making
Process
Decision

Knowledge

Experience, Theory,
Literature, Inferential
Statistics, Computers

Information
Descriptive Statistics,
Probability, Computers

Begin Here:
Identify the
 Problem

Data