Research methods Assignment Example | Topics and Well Written Essays - 2000 words

Research methods - Assignment Example One of the major sources that can lead to invalidity and unreliability in a research is the bias of the researcher (Baumgarten 2012). Biases in research are mainly categorized into selection bias, measurement bias, and analysis bias (CEMÂ  - Research -Â  Bias & Confounding n.d.). The present study focuses on learning about the different types on bias in research studies with specific examples for each of the types. Bias and Types of Bias in Research Studies: Bias is said to have occurred in a research when the outcomes of the research are different from the actual results. For example, if a research is focused on determining the risk of a disease and the results of the research reflect consistent overestimation of the risks, then the study can be said to have been based on bias. Design of a research is largely responsible for a bias and bias in general presents error in the same direction for a repeated number of the experiments for a particular research sample and work (World Heal th Organization 2001). Thus biases need to be reduced in order to produce a reliable and valid research. Types of Bias with Examples: Selection Bias: Selection bias is defined as the bias when some participants are favored and selected over others while sampling is conducted and the research outcomes are based on experiments conducted on such samples, thereby affecting the external validity of the research (Gravetter and Forzano 2010). It is also referred to as sampling bias. As a result of such bias, the outcome of the research reflects a systematic difference between those subjects that are included and those that are not. Thus either the results are underestimated or overestimated in terms of their statistics, rates, and ratios (Peat, Mellis and Williams 2002). This means that the study cannot be considered as reliable for use. Moreover, with different outcomes than the actual results, the validity of the research also gets reduced. An example of selection bias in research is a c omparison of patients in one hospital where a new wound dressing method is applied on them, with patients of another hospital who are offered the standard method of treatment. In such a case the possibility of selection bias is significantly high since different patients in different hospitals differ in their social and biological characteristics. Thus such a research is exposed to selection bias (Stommel and Wills 2004). Allocation bias is a type of selection bias that occurs when there is a difference in the characteristics of the different samples put in different trial groups of a particular research experiment, and has significant influence on the outcomes of the research (Peat, Mellis and Williams 2002). Measurement Bias: Measurement bias is defined as the bias that occurs when biases or errors occur in the process of measurement and calculations of the data based on which the results are obtained. Such biases can result from erroneous tools of measurement, errors in calculati ons, errors while measurements are recorded, participant bias, recall bias, and so on (Howlett, Rogo and Shelton 2013). For example, if dietary recalls are considered for a 24 hours time period, then measurement biases can occur with the methods of the interview, the assumptions of coding, or