Notes Measurements Describing Data Words You Need to

Notes Measurements Describing Data

Words You Need to Know… Measurement: a type of observation, a form of data

Words You Need to Know… Measurement: a type of observation, a form of data Qualitative Data: descriptive observation Ex: hot, cold, heavy, light, big, blue, furry

Words You Need to Know… Measurement: a type of observation, a form of data Qualitative Data: descriptive observation Ex: hot, cold, heavy, light, big, blue, furry Quantitative Data: numerical observation that includes both a number; measured Ex: 12 in, 13. 5°C, 25 kg, 17 L

Uncertainty There is uncertainty in all measurements, which is a range of possible values within the range of where the true value lies. + / - half of the smallest measurement

Uncertainty There is uncertainty in all measurements, which is a range of possible values within the range of where the true value lies. ± half of the smallest measurement

Well, what about the certain digits? The “certain” digits include all numbers read directly off of the measuring device PLUS one extra estimated digit. Ex: This device is a graduated cylinder. The units are m. L. The proper reading should be:

Accuracy v. Precision • Accuracy: How close a measurement is to the true or accepted value Precision: How close multiple measurements are to each other Ex: Weighing a 50 g mass Accurate/Precise? 50. 00 g 49. 99 g 50. 00 g Accurate/Precise? 32. 18 g

An easy way to remember… ACcurate = Correct PRecision = Reproducibility