Save
or

or

taken

why

Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.

focusNode
Didn't know it?
click below

Knew it?
click below
Don't know
Remaining cards (0)
Know
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size     Small Size show me how

# Lecture 3

### FDSN 507 Midterm 1

Define accuracy. How close a particular measure is to the true or correct value.
Define precision. How reproducible or how close replicate measurements are.
To determine accuracy, compare the ______ to the true value. mean
Accuracy is assessed by _____ error or _____ error. absolute, relative
Define absolute error. The difference between experimental value and true value.
Define relative error. Compares the difference between experimental value and true value against the true value.
T or F: Absolute error is more useful than relative error. False
How can precision be assessed? Standard deviation, coefficient of variation, confidence interval, standard error
Define standard deviation. How close a set of values are to each other.
Define coefficient of variation. Relative standard deviation.
A confidence interval uses ____ values for more than 25 samples and ____ values for less than 25 samples. Z, t
Define systematic error. Results which consistently deviate from true value.
Define random error. Results which fluctuate; unavoidable.
Define blunders. Results which are completely off; "screw up".
Define sensitivity. The magnitude of change in measurement with change in concentration of a compound.
Define limit of detection. The lowest possible increment that statistical significance can be detected.
What two values are similar to limit of detection? Method detection limit, limit of quantitation
What are standard curves used for? To determine unknown concentrations.
______ regression is most often used to construct a curve. Linear
Define correlation coefficient. How well data fit to a straight line.
Define coefficient of determination. How much of a measurement is explained by regression.
What is the Q test used for? To determine if outliers are present in data and whether or not they should be accepted or rejected.
What three things should a sampling plan be? Simple and flexible, protect consumers and vendors, ensure reliable results.
To ensure that the estimated value obtained from the ______ _______ is a good representation of the true value of the ______ it is necessary to develop a ______ ______. laboratory sample, population, sampling plan
What details should be included in a sampling plan? Sample size, locations, method, preservation
Define official samples. Samples selected for official or legal requirements by government.
Why might raw materials be analyzed? To ensure they are good quality.
Techniques for monitoring _____ _____ samples must be capable of producing precise results in a short time. process control
Define attribute property. Something a product either does or does not have.
Define variable property. Something that can be measured on a continuous scale.
T or F: Variable sampling requires less samples than attribute sampling. True
Give an example of a finite population. A truckload of apples.
Give an example of an infinite population. A conveyor belt which operates continuously.
Define a continuous population. A population which has no separation between different parts of the sample.
Define a compartmentalized population. A population which is split up into subunits.
Define heterogeneous population. The properties of an individual sample vary with location.
Define acceptance sampling. Determine if a shipment of products or ingredients has the quality to be accepted.
Define skip-lot sampling. Only a fraction of the submitted lots is inspected; only can do with a trusted supplier.
What is the consumer's risk associated with samapling? Probability of accepting poor quality population <5% of the lots.
What is the producer's risk associated with sampling? Probability of rejecting good quality population 5-10% of the lots.
Describe how flour sampling is conducted. Square root of number of sacks in the lot; draw sample from corner diagonal to center; draw sample from opposite corner; store sample in dry place
Give examples of manual sampling. Sample from different locations, mix properly
T or F: Continuous sampling is more prone to human bias. False
In _____ sampling, an investigator selects a sample deliberately. nonprobability
How should a sample size be determined? Precision or power analysis
Precision analysis is based on a _____ _____. confidence interval
Name three problems in sampling procedures. Sampling bias, sample degradation due to storage, mistaken sample identification
Name two methods of sample grinding. Rototap, mesh number
What is a rototap? An instrument which separates small particles based on size.
Define mesh number. Number of square openings per linear inch.
A mesh number of ___ should be used for moisture, protein, or mineral analysis. 20
Name three considerations for sample preparation. Enzyme activity, lipid oxidation, microbial growth, physical changes
Created by: goberoi

Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

• SPACEBAR - flip the current card
• LEFT ARROW - move card to the Don't know pile
• RIGHT ARROW - move card to Know pile
• BACKSPACE - undo the previous action

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

# Pass complete!

 "Know" box contains: Time elapsed: Retries:
restart all cards