Explain the four different levels of measurements and provide example(s) for each level (1 point). 2. Explain validity and reliability and discuss why validity and reliability issues are so important in the construction of any instrument (1 point). 3. To measure variables, you can develop your own instrument or use a standardized instrument. Explain how you can find a standardized instrument (1 point). 4. Assume that you plan to measure research participant's "age" for your research project. (1) Develop the survey items to measure the variable of "age" with each of the following levels: Age variable at nominal level, Age variable at ordinal level, Age variable at ratio level; (2) Explain which level of measurement can collect most in-depth information about "age" variable and why (2 points)