Fair testing and forensics

Question 1

what is a fair test

Answer 1

a fair test is when one factor is changed at a time and all other variable remain the same.

Question 2

independent variable

Answer 2

what is the thing that will be different each time you dot the experiment

Question 3

dependent variable + example

Answer 3

what are you measuring?

temperature

Question 4

How to ensure accuracy and reliability in investigations

Answer 4

is it valid?- does the info relate to the problem/ question being investigated
is it reliable? .gov, .org, .edu etc.

Question 5

Data table rules

Answer 5

label
use ruler and pencil
table columns
write units in heading boxes only
left most column for independent variable
include average column

Question 6

describe the scientific method

Answer 6

A process for experimentation that is used to explore observations and answer questions.

Question 7

goal of the scientific method

Answer 7

to discover cause and effect relationships by asking questions
carefully gathering and examining evidence
using all available info to see if it can be combined to make a logical answer

Question 8

what is the scientific method

Answer 8

ask a question
do background research
construct a hypothesis
test with experiment
procedure working
yes or no= carefully check all steps and set up go back to test with experiment
if yes analyse data and draw conclusions
results align partially or not at all with hypothesis= ask a new question experiment again return to construct a hypothesis or
results align with hypothesis
if results align with hypothesis communicate results

Question 9

what are trends

Answer 9

Trends are general directions of data

Question 10

patterns in data

Answer 10

after data is collected it can be analysed by looking for trends, patterns and relationships

Question 11

product claims- the role of science

Answer 11

do to false advertising being so common science can be used to evaluate the claims made by companies. To test if something is valid scientific evidence needs to support these claims to help us push through the fake claims.

Question 12

what is forensics

Answer 12

forensics is a tool that uses science to help solve crimes by determining who committed them and how

Question 13

forensic scientists

Answer 13

these are experts in the application of scientific methods and techniques to matters under investigation by a court of law.
They examine evidence using the scientific method, make predictions, test them and draw conclusions

Question 14

evidence

Answer 14

the available body, facts or info indicating whether a proposition is true valid or false

Question 15

fibres

Answer 15

a form of trace evidence that can be transferred from a fabric source such as carpet, clothing, bed or furniture

Question 16

Dna profiling

Answer 16

technology used in crime scene identification
DNA profiling can prove a persons identity except in the case of identical twins
DNA sequences can be made visible as X-ray lines that look like a bar code. These ‘bar codes’ give a unique pattern for every person

Question 17

Facial recognition technologies

Answer 17

is used to identify individuals using facial characteristics
it is the least intrusive and fastest biometric technology
used to know ones true identity

Question 18

when is facial recognition technology important

Answer 18

when:
crossing an international border
claiming monet from the government, institutions and or individuals
when gaining access to sensitive files

Question 19

What facial recognition technology cane be used to identify fraud

Answer 19

biometric facial recognition

Question 20

biometric facial recognition

Answer 20

the software allows a computer to identify people by their faces. It measures the position of your facial features and compares them with those of photographs on pre existing files.
It is used at airports

Question 21

Fingerprint scans

Answer 21

typically works by first recording fingerprint scans of individuals. These scans are saved within a database.
It utilises an electrical current. The ridges of your skin are electrically non conductive whereas the valleys of your fingertips are conductive. When touching a fingerprint sensor it measures the minutest differences in conductivity caused by the presence of ridges.

Question 22

fingerprint inks

Answer 22

Before the digital scanning technologies fingerprinting was done using ink and a card. A persons finger is cleaned using alcohol to remove any sweat and is then dried. The person rolls their finger in ink. Then makes an impression on card by rolling each finger from one side of the fingernail to the other.

Question 23

Iris

Answer 23

the iris is the coloured rings of muscle in the eye that controls the size of the pupil
The iris has patterns and colouring that is extremely complex
each person has a unique pattern and each eye is different making it a better method of identification than a fingerprint.

Question 24

iris scans

Answer 24

first stage- enrolment system sees you for the first time and learns to recognise you. A person stands in front of a camera and has their eyes digitally photographed in ordinary light and infrared. The photos are analyses by the computer where unnecessary details are removed and identifies around 240 unique features. These features are turned into an iris code that is stored.

Question 25

retina

Answer 25

retina is the rear of the eye and its pattern of blood vessels is even better than the iris in proof of identity.

Question 26

retina scans

Answer 26

It is performed by casting an unperceived beam of low energy infrared light into a persons eye as they look through the scanners eyepiece this bam of light traces a standardised path of the retina

Question 27

contact evidence + example

Answer 27

evidence that results from physical contact | finerprints

Question 28

trace evidence + examples

Answer 28

tiny fragments of physical evidence | hairs, fibres

Question 29

hairs

Answer 29

a form of trace evidence that can come from the criminals and appear a a crime scene

Question 30

impressions

Answer 30

it is created when two objects come in contact with enough force to cause an impression

Question 31

forged documents

Answer 31

criminals sometimes use fake signatures and documents to get what they want forensics can help determine if a signature/ document is real and/ or who wrote something

Question 32

handwriting

Answer 32

``` things to detect: layout the slant the pressure whether they underline their signature rounded letters ```

Question 33

papers and inks

Answer 33

paper differs in texture, absorbencies, presence of watermark and weight. These affect the way an ink is spread and absorbed as well ad the way each individual letter appears.

Question 34

chromatography

Answer 34

uses a solvent such a s water or alcohol to dissolve and separate an ink into its component pigments in this way the ink can be used to match a signature, letter or printed, can be matched with a suspects pen or printer

Question 35

the impacts of forensic science on society

Answer 35

countless convictions have been based heavily upon forensic evidence and testimony dna fingerprinting has led to more conviction especially in cases of sexual assault ( body fluids can be matched with a suspects dna) the exonerations of many former criminals cold cases have been reopened and solved an increase in the popularity of books and shows based on the field.

Question 36

what is leotards exchange principal in forensics

Answer 36

it states that the perpetrator of a crime will bring something into the crime scene and with something from it, both can be used in forensic evidence

Question 37

what evidence can a criminal leave

Answer 37

fingerprints, footprints, hair, skin, blood, body fluids, pieces of clothing etc.

Question 38

evidence the criminal takes away + examples

Answer 38

when the criminal comes into contact with anything at a crime scene a criminal takes part of that scene with them whether its hair or any other type of trace evidence

Question 39

how does biofacial recognition work

Answer 39

face recognition algorithms identify facial features by extracting landmarks, or features, from an image of the subject's face. For example, an algorithm may analyze the relative position, size, and/or shape of the eyes, nose, cheekbones, and jaw. ... A probe image is then compared with the face data.

Question 40

where does a voltmeter and ammetre go in a circuit

Answer 40

A voltmeter is connected in parallel with a device to measure its voltage, while an ammeter is connected in series with a device to measure its current.