A higher response rate can be obtained if follow-up questionnaires are sent, but this can add to the cost and time. However, some sociologists may choose to use questionnaires as there is no need to recruit and train interviewees thus saving costs. Another reason as to why some sociologists choose not to use questionnaires when conducting research is because of the fact that questionnaires are snapshots of social reality of the time when the respondents answer the questionnaires. This means that they fail to produce valid pictures as they do not capture how people’s attitudes can change over time. On the other hand, questionnaires tend to be used by sociologists as they provide less ethical issues than other research methods.
9. In not rejecting the null hypothesis, we are actually saying that our sample data does not allow us to reject the null hypothesis. Thus, the null hypothesis is true. 10. If we do not reject the null hypothesis based on sample evidence, we have proven beyond doubt that the null hypothesis is true.
Confidence Interval Memo Research and Evaluation I/RES 341 Dr. Richard Stanley August 10, 2008 Confidence Interval Memo Team B is preparing this memo to determine the reliability of the data we collected. We will use the statistical concept of confidence interval to determine the reliability of our research. The probability that a confidence interval includes the true mean of a data set is called the confidence level and commonly expressed as 90%, 95% or 99%. The confidence level is the area under the curve of a sampling distribution that is normal. The rule of thumb is that the number of observations should be greater than 30 to assume a normal, symmetric population without outliers in the data set.
STAT 1008 Assignment One Question 1 (a) The main purpose of statistics is that when the size of the population is not manageable, a sample of manageable size should be drawn from the population. While we are ultimately interested in some numerical aspect of the population, we also hope that some numerical aspect of the sample would reflect the numerical aspect of the population that we are interested in. Thus, there is no need to use census. (b) Stratified sampling is recommended. Stratified sampling is commonly used in the scenario described in the assignment spec.
Any arrests outside of the state would not be included as the date of failure. An additional limitation of the study is that it is possible that the relationship between drug treatment and reduced recidivism is due to unmeasured and unknown variables predicting both. The final limitation is that the research does not differentiate between in-program recidivism and post-program recidivism. Be able to differentiate between the two is necessary because of the probability that subjects behave differently when being directly supervised by the court. Despite the limitations found in the BCDTC, the findings of the research proved that subjects who participated in the DTC were less likely to be rearrested than the control group.
is biased, so we could make incorrect conclusions about model fit Detecting Heteroskedasticity: 1. Plot the regression residuals/errors, the “ehats,” or the squared residuals, the "ehats-squared", against the X variables (you should plot the residuals against each X variable separately to check which of the X variables might be a source of Heteroskedasticity). a. If Heteroskedasticity is not present, the variation in the ehats around (above and below) zero will be the same for all values of X. Figures 1a and 1b below are examples of residual plots when Heteroskedasticity is NOT present.
Now suppose that the government imposes a price ceiling, limiting rents to a price below the equilibrium price—say, no more than $800. Figure 8.2 shows the effect of the price ceiling, represented by the line at $800. At the enforced rental rate of $800, landlords have less incentive to offer apartments, so they won’t be willing to supply as many as they would at the equilibrium rate of $1,000. They will choose point A on the supply curve, offering only 1.8 million apartments for rent, 200,000 fewer than in the unregulated market. At the same time, more people will want to rent apartments at a price of $800 than at the equilibrium price of $1,000; as shown at point B on the demand curve, at a monthly rent of $800 the quantity of
Heasley Posted 9:42 PM Post Link 23 Comments Links to this post 23 Comments: At 3/05/2012 10:16 PM, ws4whgfb said... Why single out medical care? Food is more essential to life than medical care. Why not exempt the cost of food from taxes if provided by the employer? Because the way insurance works they give a discount if you are part of a large group. It spreads the risk making the cost per person less.
Also this can rule out fluke answers which can be ignored. This is then why sociologists like to use questionnaires when conducting research. Questionnaires pose fewer ethical issues than other research methods. With questionnaires some intrusive questions may be asked but it is under the respondent’s choice whether they want to answer that specific question or not. There should be guaranteed anomity so they know that anything that is answered will not be brought back to them as the questionnaire is anonymous.
The difference could simply have arisen because of a data entry typo – don’t panic or go yelling and the wrong people for the wrong things! Begin by making sure what you are looking at is accurate. In all other cases a Budget Variance is the result of either: * A price that was different from