An alternative to using passwords for authentication in logical or technical access control is biometrics. Biometrics are based on the Type 3 authentication mechanism-something you are. Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 37.

The differential backup method only copies files that have changed since the last full backup was performed. It is additive in the fact that it does not reset the archive bit so all changed or added files are backed up in every differential backup until the next full backup. The "additive backup method" is not a common backup method.

Explanation/Reference:
Unfortunately, anomaly detectors and the Intrusion Detection Systems (IDS) based on them often produce a large number of false alarms, as normal patterns of user and system behavior can vary wildly. Being only able to identify correctly attacks they already know about is a characteristic of misuse detection (signature- based) IDSs. Application-based IDSs are a special subset of host-based IDSs that analyze the events transpiring within a software application. They are more vulnerable to attacks than host-based IDSs. Not being able to identify abnormal behavior would not cause false positives, since they are not identified.
Source: DUPUIS, Cl?ment, Access Control Systems and Methodology CISSP Open Study Guide, version
1.0, march 2002 (page 92).

This type of supporting evidence is used to help prove an idea or a point, however It cannot stand on its own, it is used as a supplementary tool to help prove a primary piece of evidence. Corrobative evidence takes many forms.
In a rape case for example, this could consist of torn clothing, soiled bed sheets, 911 emergency calls tapes, and prompt complaint witnesses.
There are many types of evidence that exist. Below you have explanations of some of the most common types: Physical Evidence
Physical evidence is any evidence introduced in a trial in the form of a physical object, intended to prove a fact in issue based on its demonstrable physical characteristics. Physical evidence can conceivably include all or part of any object.
In a murder trial for example (or a civil trial for assault), the physical evidence might include DNA left by the attacker on the victim's body, the body itself, the weapon used, pieces of carpet spattered with blood, or casts of footprints or tire prints found at the scene of the crime. Real Evidence Real evidence is a type of physical evidence and consists of objects that were involved in a case or actually played a part in the incident or transaction in question.
Examples include the written contract, the defective part or defective product, the murder weapon, the gloves used by an alleged murderer. Trace evidence, such as fingerprints and firearm residue, is a species of real evidence. Real evidence is usually reported upon by an expert witness with appropriate qualifications to give an opinion. This normally means a forensic scientist or one qualified in forensic engineering.
Admission of real evidence requires authentication, a showing of relevance, and a showing that the object is in "the same or substantially the same condition" now as it was on the relevant date. An object of real evidence is authenticated through the senses of witnesses or by circumstantial evidence called chain of custody.
Documentary Documentary evidence is any evidence introduced at a trial in the form of documents. Although this term is most widely understood to mean writings on paper (such as an invoice, a contract or a will), the term actually include any media by which information can be preserved. Photographs, tape recordings, films, and printed emails are all forms of documentary evidence.
Documentary versus physical evidence A piece of evidence is not documentary evidence if it is presented for some purpose other than the examination of the contents of the document. For example, if a blood-spattered letter is introduced solely to show that the defendant stabbed the author of the letter from behind as it was being written, then the evidence is physical evidence, not documentary evidence. However, a film of the murder taking place would be documentary evidence (just as a written description of the event from an eyewitness). If the content of that same letter is then introduced to show the motive for the murder, then the evidence would be both physical and documentary.
Documentary Evidence Authentication Documentary evidence is subject to specific forms of authentication, usually through the testimony of an eyewitness to the execution of the document, or to the testimony of a witness able to identify the handwriting of the purported author. Documentary evidence is also subject to the best evidence rule, which requires that the original document be produced unless there is a good reason not to do so. The role of the expert witness
Where physical evidence is of a complexity that makes it difficult for the average person to understand its significance, an expert witness may be called to explain to the jury the proper interpretation of the evidence at hand. Digital Evidence or Electronic Evidence
Digital evidence or electronic evidence is any probative information stored or transmitted in digital form that a party to a court case may use at trial.
The use of digital evidence has increased in the past few decades as courts have allowed the use of e-mails, digital photographs, ATM transaction logs, word processing documents, instant message histories, files saved from accounting programs, spreadsheets, internet browser histories, databases, the contents of computer memory, computer backups, computer printouts, Global Positioning System tracks, logs from a hotel's electronic door locks, and digital video or audio files.
While many courts in the United States have applied the Federal Rules of Evidence to digital evidence in the same way as more traditional documents, courts have noted very important differences. As compared to the more traditional evidence, courts have noted that digital evidence tends to be more voluminous, more difficult to destroy, easily modified, easily duplicated, potentially more expressive, and more readily available. As such, some courts have sometimes treated digital evidence differently for purposes of authentication, hearsay, the best evidence rule, and privilege. In December 2006, strict new rules were enacted within the Federal Rules of Civil Procedure requiring the preservation and disclosure of electronically stored evidence. Demonstrative Evidence Demonstrative evidence is evidence in the form of a representation of an object. This is, as opposed to, real evidence, testimony, or other forms of evidence used at trial.
Examples of demonstrative evidence include photos, x-rays, videotapes, movies, sound recordings, diagrams, forensic animation, maps, drawings, graphs, animation, simulations, and models. It is useful for assisting a finder of fact (fact-finder) in establishing context among the facts presented in a case. To be admissible, a demonstrative exhibit must "fairly and accurately" represent the real object at the relevant time. Chain of custody
Chain of custody refers to the chronological documentation, and/or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of evidence, physical or electronic. Because evidence can be used in court to convict persons of crimes, it must be handled in a scrupulously careful manner to avoid later allegations of tampering or misconduct which can compromise the case of the prosecution toward acquittal or to overturning a guilty verdict upon appeal.
The idea behind recoding the chain of custody is to establish that the alleged evidence is fact related to the alleged crime - rather than, for example, having been planted fraudulently to make someone appear guilty.
Establishing the chain of custody is especially important when the evidence consists of fungible goods. In practice, this most often applies to illegal drugs which have been seized by law enforcement personnel. In such cases, the defendant at times disclaims any knowledge of possession of the controlled substance in question.
Accordingly, the chain of custody documentation and testimony is presented by the prosecution to establish that the substance in evidence was in fact in the possession of the defendant.
An identifiable person must always have the physical custody of a piece of evidence. In practice, this means that a police officer or detective will take charge of a piece of evidence, document its collection, and hand it over to an evidence clerk for storage in a secure place. These transactions, and every succeeding transaction between the collection of the evidence and its appearance in court, should be completely documented chronologically in order to withstand legal challenges to the authenticity of the evidence. Documentation should include the conditions under which the evidence is gathered, the identity of all evidence handlers, duration of evidence custody, security conditions while handling or storing the evidence, and the manner in which evidence is transferred to subsequent custodians each time such a transfer occurs (along with the signatures of persons involved at each step).
Example
An example of "Chain of Custody" would be the recovery of a bloody knife at a murder scene: Officer Andrew collects the knife and places it into a container, then gives it to forensics technician Bill. Forensics technician Bill takes the knife to the lab and collects fingerprints and other evidence from the knife. Bill then gives the knife and all evidence gathered from the knife to evidence clerk Charlene. Charlene then stores the evidence until it is needed, documenting everyone who has accessed the original evidence (the knife, and original copies of the lifted fingerprints).
The Chain of Custody requires that from the moment the evidence is collected, every transfer of evidence from person to person be documented and that it be provable that nobody else could have accessed that evidence. It is best to keep the number of transfers as low as possible.
In the courtroom, if the defendant questions the Chain of Custody of the evidence it can be proven that the knife in the evidence room is the same knife found at the crime scene. However, if there are discrepancies and it cannot be proven who had the knife at a particular point in time, then the Chain of Custody is broken and the defendant can ask to have the resulting evidence declared inadmissible.
"Chain of custody" is also used in most chemical sampling situations to maintain the integrity of the sample by providing documentation of the control, transfer, and analysis of samples. Chain of custody is especially important in environmental work where sampling can identify the existence of contamination and can be used to identify the responsible party.
REFERENCES: Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 23173-23185). Auerbach Publications. Kindle Edition. http://en.wikipedia.org/wiki/Documentary_evidence http://en.wikipedia.org/wiki/Physical_evidence http://en.wikipedia.org/wiki/Digital_evidence http://en.wikipedia.org/wiki/Demonstrative_evidence http://en.wikipedia.org/wiki/Real_evidence http://en.wikipedia.org/wiki/Chain_of_custody

If a category does not exist then you cannot compare it. Incomparable is when you have two disjointed sensitivity labels, that is a category in one of the labels is not in the other label.
"Because neither label contains all the categories of the other, the labels can't be compared.
They're said to be incomparable"
COMPARABILITY:
The label:
TOP SECRET [VENUS ALPHA]
is "higher" than either of the labels:
SECRET [VENUS ALPHA] TOP SECRET [VENUS]
But you can't really say that the label:
TOP SECRET [VENUS]
is higher than the label:
SECRET [ALPHA]
Because neither label contains all the categories of the other, the labels can't be compared.
They're said to be incomparable. In a mandatory access control system, you won't be allowed access to a file whose label is incomparable to your clearance.
The Multilevel Security policy uses an ordering relationship between labels known as the dominance relationship. Intuitively, we think of a label that dominates another as being "higher" than the other. Similarly, we think of a label that is dominated by another as being "lower" than the other. The dominance relationship is used to determine permitted operations and information flows.
DOMINANCE
The dominance relationship is determined by the ordering of the Sensitivity/Clearance component of the label and the intersection of the set of Compartments.
Sample Sensitivity/Clearance ordering are:
Top Secret > Secret > Confidential > Unclassified
s3 > s2 > s1 > s0
Formally, for label one to dominate label 2 both of the following must be true:
The sensitivity/clearance of label one must be greater than or equal to the sensitivity/clearance of label two.
The intersection of the compartments of label one and label two must equal the compartments of label two.
Additionally:
Two labels are said to be equal if their sensitivity/clearance and set of compartments are exactly equal. Note that dominance includes equality.
One label is said to strictly dominate the other if it dominates the other but is not equal to the other. Two labels are said to be incomparable if each label has at least one compartment that is not included in the other's set of compartments.
The dominance relationship will produce a partial ordering over all possible MLS labels, resulting in what is known as the MLS Security Lattice.
The following answers are incorrect:
The number of classification in the two labels is different. Is incorrect because the categories are what is being compared, not the classifications.
Neither label contains all the classifications of the other. Is incorrect because the categories are what is being compared, not the classifications.
the number of categories in the two labels is different. Is incorrect because it is possibe a category exists more than once in one sensitivity label and does exist in the other so they would be comparable.