Sucul Hayvan deneyleri
Experimental Design and Modeling in Fish Test
R&D: Definition
Research and experimental development (R&D) comprise creative work undertaken on a systematic basis in order to
increase the stock of knowledge, including knowledge of man, culture and society, and the use of this stock of
knowledge to devise new applications.
Basic research
is experimental or theoretical work undertaken primarily to acquire new knowledge of the
underlying foundation of phenomena and observable facts, without any particular
application or use in view.
Example
Applied research
Applied research
is also original investigation undertaken in order to acquire new knowledge. It is,
however, directed primarily towards a specific practical aim or objective.
Example
Continuum of research and
development
Experimental development
Experimental development
is systematic work, drawing on existing knowledge gained from research and/or practical experience, which is
directed to producing new materials, products or devices, to installing new processes, systems and services, or to improving substantially those already produced or installed.
We will cover this morning
• What is a scientist?
• What is the scientific method?
• How to design and execute an experiment.
• How to develop a simple model.
• Example of a teaching model – fish tests
A scientist – Someone who uses the scientific method to solve problems.
• So what is the scientific method?
a) Formulate a question.
b)Design an experiment to answer question.
c) Carry out the experiment and collect the data.
d)Analyze the data.
e) Evaluate and verify hypothesis. Correct or incorrect.
Science is like climbing a mountain.
Only one way leads to the top. The other is blocked by cliffs, glaciers, and rock walls. How to find the way?
Don’t conquer the world in one step!
• If you try the hard way to climb the cliff you will never make it to the top. You will fall and have accomplished nothing.
• This is like a poorly designed experiment. You have achieved nothing and your experiment was a failure.
Look for the easy way!
• Well designed experiments will take you one
step at a time to the top. Each experiment must be strong to serve as a foundation for the next step. If you fall from one step, you make
corrections, retry and make it to the next step.
Scientific method
How do we find the easy way?
• Experimental Design! Don’t attack the
mountain without thinking. It is bigger and stronger than you are. But you have a brain!
• Use the scientific method – one step at a time
Data Collection and Monitoring
• This is a necessary part of understanding the world. It is very important.
• It is NOT science until it is analyzed using the scientific method.
• There is much data in Quelimane suitable for analysis leading to an advanced degree which is being ignored. Climb the mountain the easy way!
Metod
Parts of an experiment
• Develop question or hypothesis – Scientist
• Design experimental methodology – Scientist
• Collect data – Technician
• Analyze data – Scientist
• Evaluate hypothesis and verify – Scientist
Did you know that Albert Einstein never collected data and did all his experiments in his mind?
How to schedule your time as a
scientist
Division of Time
Experienced Scientist
Division of Time
Apprentice Scientist
How most students design experiments !!
Design your Experiment with care Data collection must be relevant to
your experiment.
Why are you collecting the data?
Analyze the data carefully using
appropriate statistical methods
Appropriate statistical methods
Example of
A well designed experiment
Hypothesis
Increasing salinity decreases the growth rate of Tilapia, Oreochromis
mossambicus,
Experimental design
• Aquaria of 8 different salinities 0 to 40 ppt
• 10 fish in each aquarium under identical conditions.
Measured and identified.
• Salinity, oxygen, temp and pH recorded daily
• All mortalities measured and recorded
• Maximum food provided for several weeks.
• Aquaria cleaned and water replaced daily.
• All surviving fish measured and qualitatively assessed (condition, color etc.).
• Repeat at least three times.
Analysis
• Data table of salinity vrs size, oxygen vrs size, pH vrs size and temp vrs size for 80 fish.
• Linear regression size against all variables
• Calculate correlation coefficients for all.
• Analysis of Variance with 95% statistical probability.
• Data tables provided of number, means,
variation, standard deviation and statistical results.
Conclusion
• Based upon the analysis of data, accept or reject your original hypothesis.
• Regardless of the outcome if the experiment is well done you have made one step up the mountain.
Design a new experiment and take another step.
Systems Modeling
Modeling can
• Save time and money
• Avoid mistakes
• Predict the future
• Provide insight into interactions not obvious
• Assist is the design of experiments and equipment
• BUT they must be supported by experimental work. Models are only as good as the data!
N-NO3 LC50 Value
LC
50tests
Concentrations Number Exposed
Mortalities
T 1 T 2 T 3 Mean
0,000 ppm 10 0 0 0 0
0,010 ppm 10 4 3 5 4
0,015 ppm 10 8 8 8 8
0,020 ppm 10 9 10 10 10
0,025 ppm 10 10 9 10 10
Concentrations Number Exposed Mortalities %
0,000 ppm 10 0 %0
0,010 ppm 10 4 %40
0,015 ppm 10 8 %80
0,020 ppm 10 10 %100
0,025 ppm 10 10 %100
Speramn-Karber Trim:%40.00
Speramn-Karber estimates LC50 value: 1.107 ppm
%95 lower confidence : 0,867 ppm
%95 upper confidence : 1,413 ppm
Trimmer Sperman-Karber Method LC50 96 hour test result (version 1.5).
Online link
• Experimental Design Assistant:
• https://eda.nc3rs.org.uk
