what are the types of variables?
- independent
- dependent
- secondary
- mediating value
- confounding variable
define independent variable
can influence other variables, basically the cause and is on the X axis
define dependent variable
is under the influence of other variables basically the effect and is on the Y axis
define secondary variable
something that can help characterize the sample or is important to consider in data analysis like age or gender
define mediating value
is a factor that helps explain the relationship between two other variables, typically an independent variable (cause) and a dependent variable (effect). Think of it as the middleman or the bridge that connects a cause to its effect, showing us how or why a particular effect occurs. An example would be caffenine in energy drinks which is the independent variable and sleep which is the dependent variable
define counfounding variable
- is the variable that is associated with both the independent and independent variable
- Is not the focus of the study but can influence both the independent and dependent variables, creating a false association.
- Makes it challenging to isolate the true effect of the independent variable on the dependent variable.
- Needs to be controlled for, either through study design or statistical methods, to clarify the actual relationship between the variables you’re interested in.
describe data measurment tool: food diary
self reporterd food and beverages that have been consumed over 1 or more days in real time with portion sizes and other information depending what is asked
describe data measurment tool: 24 hour recall (structured recall) and what are the advantages and disadvantages
structured interview asking the people to recall all the food and drinks they have had in th past 24 hours
advantages: there is oppurtinity to explain and clarify questions, trust betwen personal contant, can be done in person or on phone
disadvantages: needs a lot of time for completion and anaylsis, risk of bias from interviewer
define data measurment tool: food frequency questionare and what are the advantages/disadvantages
is a questionare with a list of food that aims to see the frequency of consumption of each food which will be converted into calories and nutrional values.
advantages: cheap, convience, structured and comparalble
disadvanyage: risk of low response rates, hard to get clarification, need to be able to read and write
define data measurment tool: Anthropometric,physiological and clinicial measurments and advantages/disadvantages
allows for the collection of percise and objective data of health aspects by using instruments
advantages: stated above
d= invasive, requires intrsutments and staff who are trained
define data measurment tool: structured observation
the observation and description of behaviours/events in a systemic way it allows for data retrival that is more difficult to get
define data measurment tool: structured interview
is a verbal interaction that is structured that involves collecting more complex info
detail the context of data collection methods
- Where: is it in a controlled enviorment like a lab or research facility which allows for more presicion but is less like real life or in the participants natural enviorment like at home or work where it is less controlled but more applicable to real life.
- When: the duration of the study is based on the time needed for the effect of one variable to observed and the frequency is represnatative of the number of times the measurment will be taken
- By whom: three main groups of people: principle investigators, research staff/students and health professionals
