1. What scientific ideas or theories would help you explain why you are able to use the procedures to analyze evidence?
There are different ways in which scientific theories helped me make inferences and observe the similarities differences between various pieces of evidence in the three labs. In The Ink Is Still Wet, we dipped paper strips with an ink dot on them in alcohol and water to help get a better picture of how different the four inks were by observing the colors they produced and the ways the ink climbed up the sheets of paper. Each pen mark produced a different result. This is likely because inks behave differently based on what they contain and what colors and chemicals they are made up of. Even if inks appear to be the same with the naked eye, the concentration of certain colors and chemicals is something that you can't determine just by looking at pen tips and helps you figure out what the true answer to the problem is. Without using the science behind the "simple" inks that we see, or anything else for that matter, there is no way to tell what is really going on and inferences are not nearly as accurate as they are when you use the sciences behind the components in your experiments.
2. How has your approach to lab procedures changed from the first round of labs. Are you more or less confident in you results? Why?
Since my first round of labs, I think about and analyze the evidence and results with more thought, partially because I have used some of the technology since the first set of labs, but mostly because now I know roughly how close numbers and observations should be and how well my results have to line up in order to make a good, accurate inferences. Because of this, I would say that my confidence in my inferences and results boosted slightly. Though each lab is still different and I don't entirely know what to expect, I have a better understanding of how the labs are set up and am more prepared because I know what the range of difficulty is for each lab more or less. I will not say that I felt better about the labs when going into the second round, nor did I feel that they were going to be easier after doing my first set of labs, but I do think I did have a better understanding for what these labs were about and their importance after the first round.
Monday, November 30, 2009
Friday, October 30, 2009
Blog Entry for Forensic Tri-Lab Set One
1. What role do multiple observations/experiments play in making good inferences and conclusions in each case?
By looking at a lab in a variety of different ways, things add up better. For examlple, a soil sample with a similar PH as another but a completely diferent conductivity and water absorbancy may not be a match for the crime scene soil. Had you only tested the PH of the two soils, you may not know that it doesn't match up with the crime scene soil. When you observe things in many different ways, it allows you to get a better picture and gives you a more accurate answer/inference.
2. When is it hard to be precise and how does this affect the confidence in your results? What did you do about this?
When doing the Fiber lab, I sometimes got a large piece of string to burn, sometimes a small one, and the same inacuracy went for distances from the flame. There were many instances like this when it was pretty much impossible to be precise. In the firearms lab, it was hard for me to get exact measurements of the land and groove width and many other things as well. In the soil lab, you had to pick one of the two numbers for the PH that flashed on the screen and it was hard to make sure that no water went around the edges of the filter without passing through the soil when conducting the water absorbancy. It sometimes felt weird to have to approximate the results of an experiment, but I had to stop myself and realize that in the end, we were going to be making inferences anyway about who commited a crime and that it wasn't the end of the world if something was off by a very small amount. It did, however sometimes make me fell unsure when I chose which suspect was guilty since some tiny things went wrong and I couldn't be 100% sure.
3. When can you rely on "known" data to match up and when do you need to generate your own? What is the difference?
I don't fully understand this question.
By looking at a lab in a variety of different ways, things add up better. For examlple, a soil sample with a similar PH as another but a completely diferent conductivity and water absorbancy may not be a match for the crime scene soil. Had you only tested the PH of the two soils, you may not know that it doesn't match up with the crime scene soil. When you observe things in many different ways, it allows you to get a better picture and gives you a more accurate answer/inference.
2. When is it hard to be precise and how does this affect the confidence in your results? What did you do about this?
When doing the Fiber lab, I sometimes got a large piece of string to burn, sometimes a small one, and the same inacuracy went for distances from the flame. There were many instances like this when it was pretty much impossible to be precise. In the firearms lab, it was hard for me to get exact measurements of the land and groove width and many other things as well. In the soil lab, you had to pick one of the two numbers for the PH that flashed on the screen and it was hard to make sure that no water went around the edges of the filter without passing through the soil when conducting the water absorbancy. It sometimes felt weird to have to approximate the results of an experiment, but I had to stop myself and realize that in the end, we were going to be making inferences anyway about who commited a crime and that it wasn't the end of the world if something was off by a very small amount. It did, however sometimes make me fell unsure when I chose which suspect was guilty since some tiny things went wrong and I couldn't be 100% sure.
3. When can you rely on "known" data to match up and when do you need to generate your own? What is the difference?
I don't fully understand this question.
Friday, October 2, 2009
Blog Entry for Blood Spatter Lab One
Question 1:
How did multiple drops at each height affect your results? What is the purpose of multiple trials in an experiment?
Answer:
Having multiple drops from each height made it so that if something went wrong with one drop, there were two other times to correct your mistakes. Also, if something went wrong that you were unaware of, having multiple drops is a great way to realize your mistakes. If you only drop the blood from each height once, it is extremely likely a drop will go wrong, throwing off the results.
Question 2:
What did you discover about the influence of height on blood diameter in a blood spatter?Could you now accurately infer the height at which a blood drop originated based on the diameter of a blood spatter?Why or why not?
Answer:
The higher the blood was dropped, the messier the spatter was (typically). Sometimes, there were multiple drops or splashes that occurred when blood was dropped from high heights. Other times, it ran down the side of the ruler. Still others, a bubble of air formed in the droplet, causing the drop to change. Only if no problems occur will you be able to make good inferences about the height the spatter was dropped.
Sunday, September 20, 2009
Sound of Science story
It had been a day of running. The fiesta began at one o' clock and the hours passing since 5:30 am had been too short and extremely stressful. As usual, Larry had not prepared for the speech. He often didn't, no matter how important the topic and crowd were. Everyone would be watching him intently once he stepped up and started speaking, but unless he worked his heart out, he would have nothing to say. All morning, he was in a rush to get everything ready. He would be on the spotlight for an entire hour, talking about history and government after the parade. Writing an hour long speech from scratch and dashing around town going to and from the library, office, and coffee shop for all the research needed are never going to be easy things to do.
Maya had lived in Mexico her entire life. She knew so much about the country from her politically active parents and yet, her mother had wanted her to go to the talk about her own country's history and politics. It was actually more like a party and speech than a boring talk, but still, Maya was not looking forward to it. The only bonus to it was fresh nachos. And music. Ok and maybe lots of other things too, but she was still unexcited. There would be loud people there which was the last thing she wanted when her mood was this bad. There were plenty of other things she would have rather been doing. Maya was intent on believing that it was going to be an uneventful and boring hour for her, even if there were whistles and dresses.
Roberto could not believe it was finally happening. After the countless hours of practicing, he felt unprepared for what was about to happen. At ten years old, he was going to play his trumpet -- solo. The parade and street fiesta were planned just four months ago, the moment the new president was elected. He would bring so much change to the country since he was finally going into office, everyone was consumed by the excitement. It was now 11:00. Roberto had to be on the streets by 12:45, just in case things started earlier than 1:00. He shoved down his lunch and began to play the piece one more time before his first big performance.
It could probably be seen from a plane thousands of feet in the air. The reds of dancer's dresses, shocking white and navy blue of stands, even the scent of tortillas filled the air for what seemed like miles. And it was just the beginning of what was to come. More people would stop by and shout along with the parade music later in the fiesta. One man waited along the side of the road, hunched over a stapled packet of paper, muttering to himself. A teenage girl sat on a chair, a blank expression on her face under a stand, next to a woman talking endlessly. A young boy stood in the middle of the street, golden instrument in hand next to someone around the same age with an accordion. People started to sit next to the road and dancers, musicians, chefs, and politicians poured into the street as time passed.
At a few minutes after 1:00, it began. Thousands of people piled up alongside the main street. The heat was on the edge of unbearable, but everyone was so excited for their country and the event that it didn't matter. The first group to come down the street was a band of musicians. Then female dancers with big skirts and males in jeans and Hawaiian shirts came next. The cycle repeated with slightly different people, dances, music, clothing, and tricks coming each time. People cheered and waved the flags of their country as high as they could in the air. After about forty-five minutes of parading, a man stepped up to a wooden soapbox and people fell silent. He tilted the microphone toward his mouth and the rest of the people in the audience gave up talking for listening. After one sentence, most people were already moving into the world of Mexican history and pride as the speaker continued. In two hours, the real excitement would begin as a new leader took the reins.
Maya had lived in Mexico her entire life. She knew so much about the country from her politically active parents and yet, her mother had wanted her to go to the talk about her own country's history and politics. It was actually more like a party and speech than a boring talk, but still, Maya was not looking forward to it. The only bonus to it was fresh nachos. And music. Ok and maybe lots of other things too, but she was still unexcited. There would be loud people there which was the last thing she wanted when her mood was this bad. There were plenty of other things she would have rather been doing. Maya was intent on believing that it was going to be an uneventful and boring hour for her, even if there were whistles and dresses.
Roberto could not believe it was finally happening. After the countless hours of practicing, he felt unprepared for what was about to happen. At ten years old, he was going to play his trumpet -- solo. The parade and street fiesta were planned just four months ago, the moment the new president was elected. He would bring so much change to the country since he was finally going into office, everyone was consumed by the excitement. It was now 11:00. Roberto had to be on the streets by 12:45, just in case things started earlier than 1:00. He shoved down his lunch and began to play the piece one more time before his first big performance.
It could probably be seen from a plane thousands of feet in the air. The reds of dancer's dresses, shocking white and navy blue of stands, even the scent of tortillas filled the air for what seemed like miles. And it was just the beginning of what was to come. More people would stop by and shout along with the parade music later in the fiesta. One man waited along the side of the road, hunched over a stapled packet of paper, muttering to himself. A teenage girl sat on a chair, a blank expression on her face under a stand, next to a woman talking endlessly. A young boy stood in the middle of the street, golden instrument in hand next to someone around the same age with an accordion. People started to sit next to the road and dancers, musicians, chefs, and politicians poured into the street as time passed.
At a few minutes after 1:00, it began. Thousands of people piled up alongside the main street. The heat was on the edge of unbearable, but everyone was so excited for their country and the event that it didn't matter. The first group to come down the street was a band of musicians. Then female dancers with big skirts and males in jeans and Hawaiian shirts came next. The cycle repeated with slightly different people, dances, music, clothing, and tricks coming each time. People cheered and waved the flags of their country as high as they could in the air. After about forty-five minutes of parading, a man stepped up to a wooden soapbox and people fell silent. He tilted the microphone toward his mouth and the rest of the people in the audience gave up talking for listening. After one sentence, most people were already moving into the world of Mexican history and pride as the speaker continued. In two hours, the real excitement would begin as a new leader took the reins.
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