introduction to descriprive statistics part 2

7/27/2019 Introduction to Descriprive Statistics Part 2

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PLG 500 Penaakulan Statistik

Dalam Pendidikan

(Statistical Reasoning in

Education)

Dr Norizan Esa

[email protected]

04-6532569, room: 254 (E45)

Dr Chew Cheng Meng

04-6533758, 263 (E45)


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Mengapa statistik perlu?

Memberikan bukti empirik untuk menolak atautidak menolak sesuatu teori

Menerangkan dapatan kajian

Menilai laporan kajian dalam tinjauan literatur

Merancang dan melaksanakan penyelidikan

provide empirical evidence to reject or fail to

reject a theory

explain research findings evaluate research reports in literature review

plan and conduct research


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We can gain more meaningful information

vegetables/fruits & health

broken families & discipline problems ofteenagers

Kita boleh mendapat maklumat yang lebih

bermakna- sayur-sayuran/buah-buahan & kesihatan

- keluarga berpecah & masalah disiplinremaja


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Jenis Statistik

Statistik Inferens

Inferential StatisticsStatistik Deskriptif

Decriptive Statistics

Terdiri daripada kaedah

menyusun, mempamer &meghuraikan data

menggunakan jadual, graf

dan ringkasan ukuran

Consists of methods fororganising, displaying, &

describing data by using

tables, graphs & summary

measures

Terdiri daripada kaedah

yang menggunakandapatan dari sampel untuk

membuat keputusan atau

membuat ramalan tentang

sesuatu populasiConsists of methods that

use sample results to make

decisions or predictions

about a population


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Statistik Inferens

In feren tial s tat ist ics

2 kaedah utama:

pengujian hipotesis

anggaran

2 main methods

hypothesis testing estimation

Put forward a null hypothesis

Determine whether data is strong enough

to reject the null hypothesis

Kemukakan hipothesis nol

Tentukan sama ada data cukup kukuhuntuk menolak hipotesis nol

Use sample to estimate parameter

Construct confidence interval about the

estimate

Gunakan sampel untuk membuatanggaran tentang parameter

Bina selang keyakinan bagi parameter


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Aktiviti 1

Lengkapkan borang soal selidik

Complete the questionnaire


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Rujuk soal selidik

Refer to the quest ionnaire

1. Who are the individuals that provide the

required information?2. What group do they belong to?

1. Siapakah individu yang membekalkan

maklumat?

2. Apakah kumpulan yang mereka anggotai?


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Rujuk soal selidik

Refer to the quest ionnaire

3. What type of data can be collected from the

questionnaire?

4. Can you place the data into different

categories? Describe these categories

3. Apakah jenis data yang dikumpulkan dari soal

selidik tersebut?

4. Bolehkah anda bahagikan data tersebut

kepada kategori berbeza? Jelaskan kategori itu


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Indiv iduals

any measured/observedcharacteristic of an individual e.g: weight, height, class

Individu

the objects described by a set of

data (people, animals, things)

Objek yang dijelaskan

menggunakan satu set data

(manusia, haiwan, benda)

Variable

Variabel Sebarang ciri individu yangdiukur/dicerap

cth: berat, tinggi, kelas


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Variabel/variable

Umur/age

Jantina/gender

Jenis sekolah/ type

of school

PNGK/CGPA

Statistik berguna

dalam kerjaya

Contoh/example

30 thn 5 bln., 42 thn 3

bln., 42 thn. 7bln.

Lelaki/ perempuan

Bandar/ luar bandar/

pinggir bandar

2.87, 3.12, 3.56, 3.8

SS, S, N, TS, STS


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variabel kuantitatif- dihuraikan secara berangka

quantitative variables

- described by numerical values

variabel kualitatif

- dihuraikan secara categori

quantitative variables

- described by category designations

Cth: tinggi, berat, pendapatan bulanan, skor

dalam ujian, suhu bilik

Ex: height, weight, monthly income, test score,

room temperature

Cth: jantina, jenis kereta, jenis uniform

Ex: gender, type of car, type of uniform

Diukur menggunakan

skala ordinal, skala sela/selang, skala nisbah

Measured on an

ordinal scale, interval scale, ratio scale

Diukur menggunakanskala nominal

Measured on a

nominal scale


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variabel

Umur

Jantina

Jenis sekolah

PNGK

Statistik berguna

dalam kerjaya

contoh

30 thn 5 bln., 42 thn 3

bln., 42 thn. 7bln.

Lelaki/ perempuan

Bandar/ luar bandar/

pinggir bandar

2.87, 3.12, 3.56, 3.8

SS, S, N, TS, STS

Variabel

kuantitatif

Variabel

kuantitatif

Variabel

kualitatif

Variabel

kualitatif

Variabel

kualitatif


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Jenis Variabel

Variabel bebas

Independent variable

Variabel bersandar

Dependent variable

Variabel yangdimanipulasi/diubah

Variabel that is

manipulated/changed

Variabel yang diukur

Variable that is

measured


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Contoh

Eksperimen mengkaji kesan penggunaan modul

sokongan dalam pembelajaran matematik Kumpulan eksperimen dibekalkan modul sokongan

Kumpulan kawalan tidak dibekalkan modul sokongan

Kedua-dua kumpulan diberikan ujian sebelum (ujian

pra) dan selepas (ujian pos) pengajaran

Experiment to study the effect of using a module to

support mathematics learning

Experimental group provided with module

Control group not provided with module

Both groups given pre test and post test

Variabel

tidak bersandar

Independent v

Variabel bersandar

Dependent v


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Jenis Variabel

Variabel selanjar

Continuous variable

Variabel tidak selanjar

Discrete variable

Variabel yang diukurpada skala berterusan

Variabel that is

measured on a

continuous scale

Variabel yang diukur Variable that can only

take specific values


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Example

If you report your height, time spent sleeping

last night, whether or not you went to sleep

before midnight last night, month of birth,

distance from home, whether or not you have

spoken on a cellular phone so far today,(a) Who/what are the individuals here?

(b) How many variables are here?

(c) Which are continuous variables; which are

discrete variables?


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Example

(a) Who/what are the individuals here?(b) How many variables are here?

continuous discrete

height

time spent sleeping last night

went to sleep before midnight last

nightmonth of birth

spoke on a cellular phone today


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Example

(a) If I report the average height of a person in

this class, is that a variable?

(b) If I record the percentage of students in this

class who have spoken on a cellular phone

so far today, is that a variable?


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Example 2

Summaries are not

variables.

(c) If I record the

information for everyclass taught at the

university this

semester, would they

be variables? Whatwould the individuals be

in that case?

height

time spent sleeping last

night

went to sleep before

midnight last night

month of birth

spoke on a cellular phonetoday


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Aktiviti 2

Berdasarkan borang soal selidik

kenal pasti jenis variabel

Refer to the questionnaire

identify the type of variables


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Variabel

variable

Kuantitatif

quantitative

Kualitatif

qualitative

Selanjar

continuous

T selanjar

discrete

Serahkan jawapan anda di akhir kuliah ini

Hand in your answers at the end of this lecture


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Populasi

keseluruhan kumpulan individu yang memiliki

ciri-ciri yang sama, atau data yang diperolehi

dari kumpulan ini

Population

A group of all individuals who share some

common feature or features, or the data(scores) one would obtain from that group of

individuals


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Sample

a group of individuals chosen to represent

the population data obtained from the sample is used to

infer about the population (generalisation)

Sampel

sekumpulan individu yang dipilihuntuk mewakili populasi

maklumat diperolehi daripada sampel

supaya kesimpulan tentang populasi

boleh dibuat (generalisasi)


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Saldanha and Thompson (2002)


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Parameter

angka yang menghuraikan aspek tertentu populasi,

nilai ini selalunya tidak diketahui

- a number that describes some aspect of a

population; a fixed number whose value we usually do

not know

Statistik

- angka yang menghuraikan suatu sampel, nilai boleh

berubah dari satu sampel ke sampel yang lain,

digunakan untuk menganggar parameter yang nilainyatidak diketahui

- a number that describes a sample; can change from

sample to sample; often used to estimate the value of an

unknown parameter


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parameter

Saldanha and Thompson (2002)

What is the average

height for this

population?

What is the average

height for this

sample?

What is the average

height for this

sample?

statistic


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Parameter Statistik

Min

Mean x

Sisihan piawai

Standard deviation s

Korelasi

Correlation r

introduction to descriprive statistics part 2

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