HYPOTHESIS & VARIABLE

HYPOTHESIS & VARIABLE wien – fmub

HOW TO GET SCIENCE? Logic Deductive Library Rationally world Prediction Science Hypothesis Empirical world Inductive Hypothesis Testing Statistics analysis Methods Facts

PROBLEM SOLVING CYCLE IN MEDICAL PROCESS Patient’s complaint Therapy General examination Temporary diagnosis Conclusion Pemeriksaan lanjutan

HYPOTHESIS In scientific methods: after describing the Problem define Hypothesis HYPOTHESIS • Hypo = under; thesis = truth Temporary conclusion towards problems which is needed to prove

Is hypothesis always needed ? • Survey, explorative and case study (descriptive) usually hypothesis is not needed • Mostly, the purpose of medical research is to know the relation between variables hypothesis is important

Theory : thedata which is composed systematically as a conclusion that apply generally is needed as a general guide • Concept: a thought or an abstraction of a certain comprehension towards phenomenon which is formulated generally not measurable broken down into variable measurable • Hypothesis: - is derived from theory - is needed to explain towards problem

HYPOTHESIS • A prediction or reference which is described and accepted for a moment, that can explain the facts observed, and can be used as a guide to do research (Good and Scates, 1954) • Some temporary explanation about the facts which can be observed (Trelease, 1960) • The statement that it predicts the relation between two or more variables (Kerlinger, 1973)

Hypothesis function • 1. To verify the truth of theory • 2. Gives idea to extend theory • 3. Widen knowledge about the phenomenon which is observed

Hypothesis benefits • Gives the limitation towards scope and research working • Reminds about condition of the fact and the relation between the facts which is observed • As a simple tool to focus the facts into unity • As a guidance to do verification process

Good Hypothesis • Is described in declarative sentence that is clear and the simple one • Has strong theoritical base or concept • Declare the relation between one independent variable and one or more dependent variables • Possible to be tested empirically • Should be specific and show the variables that will be measured • Is described before start the research

Good hypothesis are affected by: • Smart observation of the researcher • Imagination and creative thinking of the researcher • Analysis framework that is used • Methods and design that is choosen

HYPOTHESIS FORMULATION • Do your questions need to know the cause of the problems? • No, just to know the problems • Yes, I want to solve it  need to formulate hypothesis

Problem - Hypothesis • A tentative statement about the relation of the probably cause with the problem • Problem: “Why the heartbeat of the patient  100 per minute?” • Hypothesis :“Hyperthyroidism is the probable etiology of tachicardia” a temporary answer to the problem / question

Hypothesis (theoretical meaning) 1. Incomplete / hasn’t established statement (hypo); in term of the “truth”so, must be tested 2. The most probably answer/ explanation of research problem 3.Theoretical conclusion derived from literature study. 4. It’s an “intellectual prediction”is needed for experimental & observational analytic research

Hypothesis (technical meaning) • Statements about parameters/ variables will be tested its validity empirically using collected sample • may be: • correlational study • comparativestudy

Hypothesis should be developed through strong theoritical base, experience, other strong scientific resources One hypothesisis only allowed for one independentvariable For complicated hypothesis  must be divided

Example : “ Education level of mother has contribution role towards growth and development of child” simple but that it can not be tested by only one hypotehesis Divided into 2 sub-hypothesis: 1. The education level of mother associated with the child growth 2. The education level of mother associated with child development

“ The child who is never comunicated with adult people will be experienced with severe mental retardation” can not be tested empirically Bad hypothesis Formula is too general and more than one meaning must be avoided “Giving drug X can cure gastrointestinal function disorder” which one of gastrointestenal function (digestion, absorbtion, atau excretion?)

Hypothesis statement which is to risk: “ Studying is not affect the students performance” from the data collected there was an evidence that students who did not study can be passed  the hypothesis was proved the conclusion by students: studying is not useful it willhavedestruction effect (this is caused by anerror in describe hypothesis)

Based on hypothesis aspect, research can be divided into: 1. Hypothesis testing research 2. Hypothesis generating research

HYPOTHESIS GENERATING RESEARCH • Using medical record data  generates hypothesis For hypothesis testing, should be used theother samples set e.g. from the medical record, there are 3000 patients with congenital heart disease. when a researcher to find out whether an association among the variables generates hypothesis  test the hypothesis using the same data (DATA DREDGING) is outlaw

HYPOTHESIS TYPES 1. RESEARCH HYPOTHESIS - is aimed to make a prediction about the occuring phenomenon e.g. “ When the environment sanitazion is not good, thus transmitted disease at the area is high” “ There is an influence of smokes towards incidenceof lung cancer “

2. STATISTICAL HYPOTHESIS - H null (Ho) & H alternative (Ha) • Ho  means there is no difference between ... and.... e.g. “There is no difference between mortality rate of heart disease in urban and rural” “ There is no relationship between smokes and lung cancer” • Ha  means there is a difference / relationship  usually, it is the research hypothesis

HYPOTHESIS TESTING • Is the answer to the questions true ? • If you want to verify, you need  A SCIENTIFIC HYPOTHESIS TESTING: 1. FORMULATE the hypothesis 2. IDENTIFY AND FORMULATE the variables included in the hypothesis 3. Choose the best and efficient way (DESIGN) to collect the data based on your hypothesis 4. Choose the RIGHT METHODS TO ANALYSE AND INTERPRET 5. Make the right CONCLUSION: is the hypothesis true or false

HYPOTHESIS TESTING • It is statistical pocedure to show the validity of the hypothesis • It is needed due to the research is done at the samples (not at population), while researcher want to generalize the conclusion towards population • Hypothesis testing is done by Ho statement • Is it evidence (by facts) which is enough to refuse Ho, and that so H1 will be achieved ? is interpretated through p (probability)value • There is the probability to do mistake of hypothesis testing

The types of error in hypothesis testing

Error type I (α = significance level): - the chance to reject Ho in samples, but Ho is correct in population false positive - determined previously by the researcher - α value: 0,5 ; 0,1; 0,05; 0,01 • Error type II (β ): • - the chance to accept Ho, but in fact the Ho should be rejected α and β value can be reduced by increasing samples

VARIABLES • Is the characteristic of subject (not that subject) variously • e.g. Type of sex, Body weight, Blood pressure • The types of variable is important due to related with data collecting and analysis technique Scale of variables 1. Categorical: nominal, and ordinal scale 2. Numerical : interval, and ratio scale

Type of variables (based on its function) 1.Independent & Dependent Variable • Independent variable (risk, predictor, causa) - it’s change will alter other variable • Dependent Variabel(effect, outcome, event) - variablewhich will be changed caused by changes of independent variable Examples : • Treatment by drug Adecreasing blood pressure i vd v • Cholesterol levelis different between male student and female student

Satujenisvariabeldapatmemilikifungsi yang berbedaberdasarkankontenriset Keturunan Konsumsigaram Merokok Kegemukan KematianpadaManula Hipertensi

2. Confounding Variable (VariabelPerancu) • Is the variable which has association with dependent var. and also with independent variabelbut it’s not an intermediate variable • Identify toward confounding factor is important since it can cause wrong result. e.g. it can be concluded there is association between the variables but actually threre is no association

Relationship between variables E e Independ var. = Independen = Pengaruh = Perlakuan = Penyebab = Regressor = Treatment = Prediktor = Risiko = Kausa Outside var. Depend Variabel = Dependen = Terpengaruh = Terikat = Regressed = Efek = Outcome = Event = Respons Intermediate var Outside var. Confounding Variabel Outside var. A D Outside var. Outside var. B C

A Dependent var Independvar Intermvariable confounding Dependent var B Independvar M Not confounding Dependent var C Independvar V Relationship among independent, dependent, confounding variabel

VariabelPerancu Minum kopi PJK Merokok Terdapat asosiasi semu antara kebiasaan minum kopi dengan kejadian PJK

Variabelperancu Makanpermen Carries gigi Sikatgigi Hubunganantaramakanpermendankariesdentisdapattersembunyipadaanak yang gemarmakanpermentetapirajingosokgigi.

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HYPOTHESIS & VARIABLE