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Uncertainty in Multiclass Classification

Dr. Rishabh Pathak
1. What is Uncertainty in Classification? Uncertainty refers to the model’s confidence or doubt in its predictions. Quantifying uncertainty is important to understand how reliable each prediction is. In multiclass classification , uncertainty estimates provide probabilities over multiple classes, reflecting how sure the model is about each possible class. 2. Methods to Estimate Uncertainty in Multiclass Classification Most multiclass classifiers provide methods such as: predict_proba: Returns a probability distribution across all classes. decision_function: Returns scores or margins for each class (sometimes called raw or uncalibrated confidence scores). The probability distribution from predict_proba captures the uncertainty by assigning a probability to each class. 3. Shape and Interpretation of predict_proba in Multiclass Output shape: (n_samples, n_classes) Each row corresponds to the probabilities of ...
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Haphazard Sampling or Convenience Sampling

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Dr. Rishabh Pathak

Haphazard sampling, also known as convenience sampling, is a non-probability sampling technique where sample units are selected based on their convenient availability to the researcher. This method is characterized by its reliance on easily accessible subjects rather than random selection. Here are some key points about haphazard sampling or convenience sampling:


1.    Definition:

o    Haphazard sampling, or convenience sampling, involves selecting sample units based on their easy accessibility and convenience to the researcher.

o    Researchers choose participants who are readily available or easily reached, without following a systematic or random selection process.

2.    Characteristics:

o    Convenience sampling is a non-probability sampling method that does not involve randomization or known probabilities of selection.

o Sample units are typically chosen based on the researcher's proximity, availability, or ease of access.

3.    Process:

o    In convenience sampling, researchers may select participants who are nearby, willing to participate, or easily reachable through existing networks.

o  This method is often used when time, resources, or logistical constraints make random sampling impractical.

4.    Advantages:

o    Convenience sampling is quick, easy, and cost-effective, making it suitable for exploratory research, pilot studies, or preliminary investigations.

o  This method can be useful for generating initial insights, identifying trends, or exploring research questions in a flexible manner.

5.    Limitations:

o Results obtained from convenience samples may not be representative of the larger population due to selection bias.

o    The lack of randomization in convenience sampling can lead to sampling errors and limit the generalizability of findings.

o    Researchers should be cautious in drawing broad conclusions or making population inferences based on convenience samples.

6.    Applications:

o    Convenience sampling is commonly used in educational research, small-scale studies, qualitative research, and situations where random sampling is impractical.

o    This method is often employed in situations where the focus is on exploring phenomena, generating hypotheses, or gaining initial insights rather than making population estimates.

7.    Considerations:

o Researchers should clearly acknowledge the limitations of convenience sampling in terms of generalizability and potential bias in sample selection.

o  While convenience sampling can be a useful starting point in research, efforts should be made to supplement or validate findings with more rigorous sampling methods when possible.

Convenience sampling, or haphazard sampling, offers a practical and accessible approach to sampling in certain research contexts. While this method provides convenience and flexibility, researchers should be mindful of its limitations in terms of representativeness and potential bias. Careful consideration of the research objectives and constraints is essential when choosing convenience sampling as a sampling strategy.

 

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  1. SRIJune 29, 2024 at 2:59 AM

    Insightful to learn about Research Methods. Thanks for your effort sir (@Dr. Rishabh Pathak)

    ReplyDelete

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