Power Score
Power Score is an indicator of skill and time invested in the Stardust@Home project. Power Score is the total value of all calibration movies you have correctly identified.

New calibrations introduced in Phase IV, known as "Power Movies", have been re-assigned a difficulty value between 5 and 85 points based on the measured success of all Dusters correctly identifying each track in Phase IV.

Some Power Movies will be nearly impossible to spot (on purpose). If you miss a Power Movie, your Power Score will not go down.

Skill Score
Skill is a measure of how often you are able to identify a track when one is presented to you, expressed as a percentage.

From Phase V, Skill score will rise with every correctly identified calibration track, in proportion to Power Movie difficulty. Your skill score will go down after every missed calibration, falling a little for missed difficult Power Movies, but falling more after missing an easier one.

The Phase V Skill formula is:

Power Score / {Power Score + total Missed Power Movies (85-value)}

Certificates
Certificates will be awarded for finding tracks. We have retired the Milestone Certificates along with the previous scoring system. In Phase IV and V we will recognize any Duster who clicks on a movie containing a track, not just the first. The timeline will go like this: periodically promising movies are promoted for review by a Red Team member or by virtue of the number of positive clicks. If we review the movie and think there is a track, we promote it to the Candidates page. At that point, everyone who clicked on a movie containing that track gets a certificate. The first Duster who clicked gets the naming rights.

Incidentally, as we find new tracks we will make new Power Movies from them. Once that happens, we will not award a certificate for clicking on a candidate track movie.)

Power Movie
A focus movie for which we know the answer. We created the power movies using Stardust aerogel movies, but some of them have tracks digitally inserted. We used images of tracks from laboratory shots into Earth-bound test aerogel. When you use the Virtual Microscope, some of the focus movies you see will be power movies. They may or may not have a track in them, but they are all in focus. We use them to test your skill at recognizing tracks.

Focus Movie
A stack of images taken from a single field of view of the automated microscope at several different focus depths. Each image can be thought of as a frame in a movie; running the movie forward and backward by sliding your mouse up and down the focus bar in the Virtual Microscope is equivalent to looking throgh a real microsope and turning the focus knob.

FOV
A field of view, particularly in a microscope. Pronounced "fove".

List of Data Viewed
Listing of track candidates that you have identified.

Number of Agreements
In the My Events page: the number of people who agreed with you that a certain movie really does contain a track. This number includes yourself!

Rank
Your rank is determined by comparing your score to the scores of other volunteers. If your rank is 150, that means there are 149 volunteers who have a higher score than you do. Your rank is recalculated every few minutes.

Real Movie
An ordinary focus movie, created from the aerogel that flew on the Stardust mission. (As opposed to a Power Movie.)

Score (Phases I, II and III)
Your score is the total number of calibration movies you have identified correctly minus the number of calibration movies you have answered incorrectly. Most movies are not calibration movies, and will not affect your score. Score was replaced with Power Score in Phase IV.

Sensitivity (Phases I, II and III)
Sensitivity measures how well you are able to correctly identify calibration tracks. Sensitivity is the total number of tracks you have correctly identified in calibration movies divided by the total number of calibration movies you have searched in which there were actually tracks.

Specificity (Phases I, II and III)
Specificity measures how well you are able to correctly identify a calibration movie that contains no track. Specificity is the total number of times you have correctly found no track in calibration movies divided by the total number of calibration movies you have searched in which there were actually no tracks.

VM
Virtual Microscope, the program used by Stardust@home allowing volunteers to view focus movies from the Stardust Interstellar Dust Collector.

WCO
On the MyEvents page, in the comments column, short-hand for "Worth Checking Out".