Stratified sampling involves dividing the population into subgroups or strata based on key characteristics. Samples are then selected from each strata using simple random or systematic sampling. This technique is used to examine relationships between variables, make comparisons among subgroups, and reduce sampling error. Sample size depends on heterogeneity, with larger samples reducing sampling error.

1. Stratified Sampling First we divide the pop by certain characteristics Eg. Gender, age, etc based on key independent variables each sub-population is called stratum Each stratum is mutually exclusive set of elements

2. Cont’d finally using SRS or SS, we sample from each stratum Used to examine the r/ship b/n independent (criteria for stratification) and dependent variable; To make comparisons among sub-pop And used to reduce sampling error * prior information about the pop is required

3. Cont’d Disproportionate Stratified Sampling- equal sample size from each stratum Proportionate Stratified Sampling - proportional sample size from each stratum Note: Use SS only if there is significant difference across the strata

4. Multi-Stage Cluster Sampling For population without exhaustive list (SF) Or when it is impossible to compile a complete list of the elements (SF) Involves sampling of natural clusters Eg. Schools, kebeles, industries, etc

5. Cont’d Followed by selection of elements from the clusters using SRS or SS Eg. Addis Ababa households’ mode of transportation Involves listing and sampling at d/t stage It involves two or more sampling error

6. Stratified Multi-stage Cluster Sampling Involves grouping of clusters with similar characteristics; Then selecting clusters from each group of similar clusters; Eg. Lideta Sub-city poverty study Stratification can take place at each stage of sampling

7. Probability Proportionate to Size (PPS) Sampling In most cluster sampling small clusters tend to disproportionately represented To avoid this we give equal chance of selection Method Giving each cluster chance of selection proportionate to its size Then selecting equal sample size from each cluster

8. Cont’d Illustration: suppose we want to sample 1/10 th of 5 clusters, in which the clusters have 50,100, 200, 300 and 400 We will give a proportion of 1, 2, 4, 6 and 8 respectively PPS is used to Permit selection of more clusters Ensure representation of large clusters Equal chance of being selection to the pop

9. Cont’d PPS is applied under 3 conditions: When dealing with unevenly distributed clusters; With large sample size w/c can be broken into clusters; and When we have data on the proportion of each cluster.

10. Sample Size Sample size depends on heterogeneity of the pop, strata or cluster; size of the sub-group precision SEM=sd/√n The larger the sample size the the lower the sampling error

11. Non-probability sampling Purposive or judgmental sampling: Sample selected because of their unique position in the pop understudy; Quota Sampling : selected to represent a certain characteristics or group in a pop.

12. Measurement and Meaning Concept : is a mental image that summarize similar observations, idea, Eg. Poverty, slum, etc Conceptual Definition : specification of the meaning of each concept in a research to enable measurement Eg. Slum is ‘a heavily populated urban area characterized by substandard housing and squalor’.

13. Cont’d Operational Definition: a definition by which we make the concept measurable, using indicators. Eg. Slum- • inadequate access to safe water; • inadequate access to sanitation and other infrastructure; • poor structural quality of housing; • overcrowding; • insecure residential status.

14. Level of Measurement There are 4 levels to measure variables. Nominal Variable : mutually exclusive categories. With no ordering. Eg. Sex, marital status, etc Ordinal Variable : categories ordered or ranked in sequential manner. Eg. Class rank, social class Interval-Ratio Variable: logical, ordered and defined in terms of a standard unit of measurement.

15. Cont’d Usually have a zero point- i.e. absence Eg. Age, land area, distance from city-center etc Discrete variable- integer number of values eg. Age, family size Continuous Variable- assume a decimal number of values. Eg. Distance, area, etc Note: the statistical analysis that we apply differs to each level of measurement and to the two types of variables.

16. Instrument Design Questionnaires are set of questions or statements which we used to gather data in survey research. There are two types of questions Open-ended- respondent gives his own answer Eg. What is your attitude towards Addis trans? Close-ended- respondents selects from the choices provided Eg. How do you grade urban trans in Addis Good Fair Bad

17. Guide to Question Construction Respondents must be competent to answer Eg. What kind of planning technique should AACA apply? Use vocabulary that respondents can understand. Eg . What issues should be considered in urban development strategy? Make items clear- avoid ambiguous questions. Eg. Do you live near Mekato? How often do you visit a doctor?

18. Cont’d Avoid Negative Items- respondents might agree with the –ve one while they mean +ve one. Eg. Should not the AACA invest on infrastructure development? Avoid Double Barreled Questions- two questions in one question Eg. What is your opinion about the urban policy and its implementation in Ethiopia?

19. Cont’d Format questions in a sequential order and bring together similar questions Eg. SD, Mig. History, family condition, living condition and finally empl’t condition Avoid biased items or labels Eg. Fascist, racist, fundamentalist, etc Contingent questions should be asked to the relevant respondents. Eg. Are you married? If yes, does your spouse have a job? How old are you?

20. Cont’d The purpose of the research should have to be clearly indicated in the beginning of the questionnaire General and specific instruction of the questionnaire should have to be clearly indicated

21. Cont’d There are two types of questionnaires Self-administered – filled by the respondent him/herself; Enumerator administered- filled by an interviewer.

22. Other methods of data collection Sample survey enables us to collect data from large amount of respondents using a representative sample But its broad coverage make to gather shallow data. When we want to collect in-depth information we use: In-depth interview; Focus group Discussion; and other methods

23. In-depth Interview Used to collect detailed information using semi-structured interview guide The guide is set of generic open ended questions and probing questions The guide only lead the flow of the interview Probing is basic tool in this method Eg. What do you know about low cost housing? Probe LCH vis-à-vis affordability LCH vis-à-vis efficiency LCH vis-à-vis quality

24. Cont’d Interviewee is given freedom of expression in his own words Enable to collect depth information on our research topic Usually used with experts, officials, knowledgeable community members, etc

25. Cont’d Taking note and recording the interview is crucial Disadvantage : Heavily influenced by the interviewer skill; and Difficult to compare responses in a rigorous way.

26. Focus Group Discussion Used to gather information from a discussion of a group by giving them a topic of discussion Group interaction b/n respondents will stimulate richer responses The interviewer can observe the discussion and understand their feeling, behaviors, attitudes, etc Usually have 6-12 members and a moderator, but a group size of 8 is preferable The moderator is expected only to raise topic of discussion and facilitate the discussion

27. Cont’d The group should be a homogeneous group and it is better if they are acquainted If the FGD is handled by a skilled moderator it enables to generate detailed and valid data The moderator should control the flow of the discussion using a checklist In FGD also probing is important And the moderator has to take note and use a tape recorder

28. The Research Paper Finding and narrowing the Problem Select the general topic or issue of research (from the literature or from our experience); Review the evidence or literature review Identify the knowledge gap then we make the research problem precise every research report should have to clearly state the research problem in the beginning Research problem is the k’ge gap to be filled by the research not social problem

29. 2. Formulating Research Questions This are question that the research is going to address After clearly setting the RP, we will split the RP into specific answerable research questions Eg. RP- the K. 10 housing condition How is the structural conditions of the houses in the kebele? What services and amenities does the residents receive? How is the provision of basic infrastructure in the kebele?

30. 3. Composing the Paper Academic research report should have to be organized in a manner Introduction-literature review-methods-result-conclusion-recommendation Introduction - describes related research and explains what your work contributes and why it is important. It sketches out the objectives, research questions, hypothesis, scope and organization of the report.

31. Cont’d b) Literature Review - presents the summary of theoretical and empirical findings related with the research topic c) Methods - this section describes each steps that the study applied in collecting and analyzing the data. it presents the methodology used, the survey design, the sampling technique applied, the sample size, the composition of the sample and methods of data analysis. In addition, the characteristics of the population is described.

32. Cont’d Result - should summarize the data and the inferences drawn It should have to answer the research questions raised in the introduction It should include tables and figures to explain the variables understudy The result section should be sub-divided into sub-topics and arranged in an organized manner The result should critically analyzed using other evidences and theories

33. Cont’d Draw the conclusion from your findings and discuss the possible significance of your findings (recommendation) And indicate areas of further research

34. Editing The research report should be readable, therefore we should have to make proper editing work before submitting the report. Word Choice - avoid undefined adjectives. Eg. Deep, wonderful, near, many, little Logical connection with sentences - there should be a logical flow of sentences in a paragraph. - There should have to be coherence b/n sentences.

35. Cont’d Avoid to be & passive voice - verb to be (is, was, were, will be) and passive voice makes our description static. Avoid informal language - conveying our finding in an informal language makes to seem thoughtless. Eg. Really was not upset, didn’t, ain’t, all of a sudden etc Keep your summary, paraphrase and quotation as short as possible and harmonize the quote into your paper

36. Documentation Every works quoted or paraphrased from other sources should be properly cited. We use in-text citation (the new MLA) method. Eg. Modern urban planning has arisen in response to social and econ problems (Neil 56) or According to Neil …(56)

37. Cont’d We can also use Author-Date system Eg. Modern urban … (Neil, 2004:56) or According to Neil … (2004:56)

38. Referencing You should have to enlist every material you used in the bibliography section. Book Neil, William J.V. (2004) Urban planning and Cultural Identity. London: Routledge Books with editor Journal Morello, Jorge (2000)’Urbanization and Ecology’ . In Third World Planning Review , Vol. 22 No. 4, 2000, pp 119-132