पुढील उतारा वाचून त्यावर आधारित प्रश्नांची उत्तरे द्या :
गैर-संभाव्यता नमूना पद्धती (Non-Probability Sampling)
गैर-संभाव्यता नमूना ही अशी नमूना निवडपद्धती आहे की, जिच्यामध्ये लक्ष्य-समूहातील प्रत्येक घटकाचा नमूना निवडीमध्ये समावेश होण्याच्या संभाव्यतेचा कोणत्याही आधारावर अंदाज वर्तविणे शक्य नसते. गैर-संभाव्यता नमूना हा मुद्दाम नमूना, हेतुमूल्य नमूना आणि निर्णय नमूना अशा वेगवेगळ्या नावांनी ओळखला जातो. अशा प्रकारच्या नमून्यामध्ये संशोधकाने नमून्यातील घटकांची निवड जाणीवपूर्वक केलेली असते; घटकासंबंधी त्याची निवड ही अंतिम असते. दुसऱ्या शब्दांत सांगायचे झाल्यास, गैर-संभाव्यता नमूना चौकशीचे रचनाकार लक्ष्य-समूहातील विशिष्ट घटकांची नमून्यासाठी हेतुपूर्वक निवड, प्रचंड वस्तुमानातून छोट्या वस्तुमानाची ते संपूर्ण लक्ष्यसमूहाचे नमूनेदार उदाहरण असेल किंवा प्रतिनिधित्व करेल अशा आधारावर करतात. उदाहरणार्थ, जर एखाद्या राज्यामध्ये राहणाऱ्या लोकांच्या आर्थिक स्थितीचा अभ्यास करायचा असेल, तर सखोल अभ्यासासाठी त्या राज्यातील काही शहरे आणि खेड्यांची प्रातिनिधिक तत्त्वावर हेतुपूर्वक निवड केली जाऊ शकते. अशा प्रकारे अभ्यासाच्या रचनाकारांचा निर्णय या नमूना आराखड्यामध्ये महत्त्वपूर्ण भूमिका बजावतो.
अशा आराखड्यांमध्ये वैयक्तिक घटकाला नमूना निवडीमधील प्रवेशास खूपच संधी असते. संशोधक त्याच्या दृष्टिकोनास अनुकूल निष्कर्ष देणाऱ्या नमून्याची निवड करू शकतो आणि जर असे घडले तर संपूर्ण चौकशीचाच विचका होऊ शकतो. अशा रीतीने या प्रकारच्या नमूना तंत्रामध्ये पूर्वग्रहदूषिततेला स्थान मिळण्याचा धोका संभवतो. पण जर संशोधक निःपक्षपातीपणे, पूर्वग्रहदूषिततेविना कार्यरत असतील आणि अचूक निर्णय घेण्यासाठी आवश्यक असणारा अनुभव त्यांच्या पदरी असेल तर जाणीवपूर्वक निवडलेल्या नमून्याच्या विश्लेषणातून मिळालेले निष्कर्षसुद्धा सुसह्य होण्याइतपत विश्वसनीय असू शकतात. असे असले तरी या प्रकारच्या नमून्यांमध्ये प्रत्येक घटकाला काही प्रमाणात का असेना समाविष्ट होण्याची स्पष्टीकरणात्मक संधी मिळेलच याची खात्री देता येत नाही. या नमूना प्रकारामध्ये नमूना त्रुटींचा अंदाज व्यक्त केला जाऊ शकत नाही. पण पूर्वग्रहदूषित घटक कमी-अधिक प्रमाणात नेहमीच आढळतो. त्यामुळे, महत्त्वपूर्ण मोठी व्याप्ती असलेल्या चौकशांमध्ये या नमूना आराखड्याचा क्वचितच वापर केला जातो. असे असले तरी, कमी व्याप्ती असलेल्या चौकशा आणि वैयक्तिक संशोधनांमध्ये या आराखड्याचा स्वीकार केला जाऊ शकतो. कारण या नमूना पद्धतीमध्ये उपजतच वेळ आणि पैशांची तुलनात्मक बचत होते. कोटा नमूना हे सुद्धा गैर-संभाव्यता नमून्याचे उदाहरण आहे. कोटा नमून्यामध्ये मुलाखतदारांना सुलभपणे त्यांचा वाटा, माहिती भरण्याच्या काही निबंधासह विविध स्तरातील माहिती भरण्यासाठी दिला जातो. दुसऱ्या शब्दांत सांगायचे झाल्यास, नमून्यातील घटकांची प्रत्यक्ष निवड ही मुलाखतदारांच्या विवेकावर सोडलेली असते. ही नमूना पद्धती अतिशय सोयीस्कर आणि तुलनात्मकदृष्ट्या कमी खर्चिक आहे. परंतु, अशा प्रकारे निवडलेल्या नमून्यांमध्ये यादृच्छिक नमून्याचे गुणधर्म निश्चितपणे नसतात. कोटा नमूने हे खरंतर निर्णय नमूने असतात आणि त्या आधारावर काढलेले निष्कर्ष औपचारिक-मार्गाने काढलेल्या सांख्यिकीय उपचाराच्या कक्षेत राहणारे नसतात.
उताऱ्यामधील मध्यवर्ती कल्पना पुढीलपैकी कोणती आहे?
EN
Read the following passage and answer the questions:
Non-Probability Sampling Non-probability sampling is that sampling procedure which does not afford any basis for estimating the probability that each item in the population has of being included in the sample. Non-probability sampling is also known by different names such as deliberate sampling, purposive sampling and judgement sampling. In this type of sampling, items for the sample are selected deliberately by the researcher; his choice concerning the items remains supreme. In other words, under non-probability sampling, the organisers of the inquiry purposively choose the particular units of the universe for constituting a sample on the basis that the small mass that they so select out of a huge one will be typical or representative of the whole. For instance, if economic conditions of the people living in a state are to be studied, a few towns and villages may be purposively selected for intensive study on the principle that they can be representative of the entire state. Thus, the judgment of the organisers of the study plays an important part in this sampling design. In such a design, personal element has a great chance of entering into the selection of the sample. The investigator may select a sample which shall yield results favourable to his point of view and if that happens, the entire inquiry may get vitiated. Thus, there is always the danger of bias entering into this type of sampling technique. But if the investigators are impartial, work without bias and have the necessary experience so as to take sound judgement, the results obtained from an analysis of deliberately selected sample may be tolerably reliable. However, in such a sampling, there is no assurance that every element has some specifiable chance of being included. Sampling error in this type of sampling cannot be estimated and the element of bias, great or small, is always there. As such this sampling design gets rarely adopted in large inquiries of importance. However, in small inquiries and researches by individuals, this design may be adopted because of the relative advantage of time and money inherent in this method of sampling. Quota sampling is also an example of non-probability sampling. Under quota sampling the interviewers are simply given quota to be filled from the different strata, with some restrictions on how they are to be filled. In other words, the actual selection of the items for the sample is left to the interviewer's discretion. This type of sampling is very convenient and is relatively inexpensive. But the samples so selected certainly do not possess the characteristic of random sample. Quota samples are essentially judgement and inferences drawn on their basis are not amenable to statistical treatment in a formal way. The central idea of the passage is concerned with :
Non-Probability Sampling Non-probability sampling is that sampling procedure which does not afford any basis for estimating the probability that each item in the population has of being included in the sample. Non-probability sampling is also known by different names such as deliberate sampling, purposive sampling and judgement sampling. In this type of sampling, items for the sample are selected deliberately by the researcher; his choice concerning the items remains supreme. In other words, under non-probability sampling, the organisers of the inquiry purposively choose the particular units of the universe for constituting a sample on the basis that the small mass that they so select out of a huge one will be typical or representative of the whole. For instance, if economic conditions of the people living in a state are to be studied, a few towns and villages may be purposively selected for intensive study on the principle that they can be representative of the entire state. Thus, the judgment of the organisers of the study plays an important part in this sampling design. In such a design, personal element has a great chance of entering into the selection of the sample. The investigator may select a sample which shall yield results favourable to his point of view and if that happens, the entire inquiry may get vitiated. Thus, there is always the danger of bias entering into this type of sampling technique. But if the investigators are impartial, work without bias and have the necessary experience so as to take sound judgement, the results obtained from an analysis of deliberately selected sample may be tolerably reliable. However, in such a sampling, there is no assurance that every element has some specifiable chance of being included. Sampling error in this type of sampling cannot be estimated and the element of bias, great or small, is always there. As such this sampling design gets rarely adopted in large inquiries of importance. However, in small inquiries and researches by individuals, this design may be adopted because of the relative advantage of time and money inherent in this method of sampling. Quota sampling is also an example of non-probability sampling. Under quota sampling the interviewers are simply given quota to be filled from the different strata, with some restrictions on how they are to be filled. In other words, the actual selection of the items for the sample is left to the interviewer's discretion. This type of sampling is very convenient and is relatively inexpensive. But the samples so selected certainly do not possess the characteristic of random sample. Quota samples are essentially judgement and inferences drawn on their basis are not amenable to statistical treatment in a formal way. The central idea of the passage is concerned with :