1. Censoring is addressed in survival analysis and it occurs when the researcher has
partial information about an observation survival times but does not know the exact
survival times. There are different types of censoring, right and left censoring and
also interval censoring which are further divided into Type I and type II, Anthony,
Turkson in “Handling Censoring and Censored Data in Survival Analysis: A
Standalone Systematic Literature Revie” (Turkson, 2021) looks at these type and
more. Censoring can lead to biased results and reduce statistical power of analysis if
not handled with appropriate techniques. (Turkson, 2021).
2. Sampling bias is when the samples of a stochastic variable are collected incorrectly
and do not represent the true population because of non – randomness. (Panzeri,
2008), an example in soil measurement experiment can be collecting soil samples at
only one location because it is easily accessible which can be collecting the top part
of the soil and not going deeper.
Temporal bias which arises due to soil properties changing over time due to change
in season which leads to soil differing in each season. An example is when the soil
materialization is different through time due to varying soil conditions such as degree
of moisture or compaction (Desaules, 2012).
3. Imputing explicitly is replacing the missing value with a single estimated value, this
value can be the mean, median or mode of the available data points in the dataset.
This type of imputation can distort the original distribution of the dataset and
introduce bias (Mehrotra DV, 2017). This can be done when there are less missing
values and the missing at random.
Bibliography
Desaules, A. (2012). Measurement instability and temporal bias in chemical soil monitoring:
sources and control measures. Environmental Monitoring and Assessment, 487 502.
Panzeri, S. M. (2008). Sampling bias. Scholarpedia,, 3, 4258.
Turkson, A. J.-M. (2021). Handling Censoring and Censored Data in Survival Analysis: A
Standalone Systematic Literature Review. International Journal of Mathematics and
Mathematical Sciences, 16. Retrieved from https://doi.org/10.1155/2021/9307475