A two-tailed test is a test of statistical significance in which deviations from the null hypothesis in either direction is considered.

Alpha level refers to the probability of rejecting the null hypothesis when it is true or the chance of committing a type 2 error.

When you find a report of original research (article) related to your clinical question or any others, what characteristics of the study will you consider to determine if its findings are valid?  (Please focus on the threats to the validity/Bias of the study). List and BRIEFLY describe TWO types of bias/threats to the validity of an experimental RCT design.

A RCT has been designed to assess the effectiveness of a balance program on fall risk prevention for an adult population from 75-95 year old. Three groups are compared: a control group that receives a fall risk prevention pamphlet, a group with an exercise protocol of ankle and stepping strategies, and an exercise group of Tai Chi. All patients completed a baseline questionnaire to collect comorbidities as well as fall history and a set of objective tests consisting of the Time Up and Go test (TUG) and the Functional Reach Test (FRT). The TUG was used to screen for risk of falling while the FRT to assess changes/improvement in balance. After 4 weeks of the intervention, patients were tested again to measure progression. Additional data was collected at follow up including General health (measured by SF-12) and pain intensity (measured by numerical rating scale). A correlational analysis was completed between the two measures and a Pearson moment correlation coefficient of 0.39 was found. The results of the study suggest:

This and the next question are based on the following information: One thousand (1000) college students were recruited during their college enrollment week to examine the risk of suicidal ideation and its association with depression. The principal measure of depressive symptoms was the nine-item depression module from the Patient Health Questionnaire (PHQ-9). Additional questions were focused on suicidal ideation, suicide attempts, symptoms of anxiety and stress. The inclusion criteria included college students without any history of suicidal ideation . All participants completed the battery of questionnaires and were follow up for three years to measure the risk of developing suicidal thoughts. At the end the data of 729 students was analyzed over a 3-school year interval.  What type of study design do you believe the investigators used?  

Can a hotdog be categorized as a sandwich?

Which of the following does Systemd use to denote runlevels?

Which of the following characters can be entered at the beginning of a line in a shell script to ensure that line is recognized as a comment line only?

Which of the following commands can be used to change the priority of a running process?

Billy would like to mount the remote /data directory on server5 to the /mnt directory on his local system using NFS. Which command can he use?