Dynamic Foraging Model for Human Behavior on the internet

boorishadamantAI and Robotics

Oct 29, 2013 (3 years and 9 months ago)

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Dynamic Foraging Model
for Human Behavior on
the internet
(working title)

Bjarne Berg

1

Agenda

Introduction and Background

Optimal Foraging Theory (OFT)

Foraging Models

Economic perspective (EMH and REH)

Human Factors

Proposed Framework

Question and Answers


2

Background

Despite extensive research in the human evolution since 1854 when
Charles Darwin published his thesis on the Origin of the Species, the
motivation and the behavior associated with foraging and thereby the
natural selection through the survival of the best foragers, was not well
researched for over one hundred years.

This changed in 1966 when researchers such as Emlem published his
work on the foraging behavior of birds and by the publication the same
year of MacArthur & Pianka’s work on the individual’s selection process
of foraging areas. Over the next thirty years this research gave rise to a
large field known as Optimal Foraging Theory (OFT) that has been the
foundation in a variety of biological and zoology studies.


Only in the last ten years OFT has been extended into the field of
information technology and search algorithms (Sugawara and
Watanabe, 2002; Pui and Huosheng, 2002).

3

Background

At the same time, there has been an increased interest in the last
decade of extending OFT into a better understanding of human
behavior on the internet through intelligent foraging agents (Jiming
et. al., 2004) and through extensions to social behaviors of foraging
agents (Andrews, 2007).


Most of this research has focused on optimizing the algorithms of
robots or intelligent agents that can, on behalf of the human, scan
vast amounts of information to find specific items.

4

Agenda

Introduction and Background

Optimal Foraging Theory (OFT)

Foraging Models

Economic perspective (EMH and REH)

Human Factors

Proposed Framework

Question and Answers


5

The Optimal Foraging Theory (OFT)

In 1966 the field known as Optimal Foraging Theory (OFT) was
established through the publication of Emlen’s article on foraging
behavior of birds and by MacArthur & Pianka’s work on optimization
models the same year.

In general, the models established over the next ten years focused on
four core areas that became known as elements of a micro
-
ecological
theory. These areas include

1) What to eat (optimal diet).

2) Where to eat (optimal patch choice).

3) Optimal allocation to each patch (time).

4) Optimal patterns and speed of movements.


Combined as a whole, the micro
-
ecological theory forms the platform for
macro
-
ecological theory which has far reaching implications

6

The Optimal Foraging Theory (OFT)

Natural Selection


The optimal should already be here

Cost
-

Benefit and minimal benefit requirements

Optimal Patch Choice (OPC)


scholastic models (bird’s patch selection)

Committed exclusions and logical progressions

Sub
-
optimal foraging


social and cultural constraints

Compression Hypothesis
-

as the number of competing species
increase, a reduction in the patches used occur & the range of items
consumed remains constant or only slightly increase .

Specialization


Koala Bears (increased food abundance leads to greater
food preference)



7

Agenda

Introduction and Background

Optimal Foraging Theory (OFT)

Foraging Models

Economic perspective (EMH and REH)

Human Factors

Proposed Framework

Question and Answers


8

Foraging Models

Optimal Diet Theory (ODT)
-

also includes advanced mechanisms for
gradual shifts in item acquisitions when preferable items (high net benefit)
exists or becomes more abundant.

Optimal Time Allocation (OTA) and Marginal Value Theorem
(Chernov, 1976),
and
Surrender Time

Evolutionary foraging algorithms

The simplest approach to account for the dynamically changing
environment has been to introduce uncertainty/variability into the
approach and rebuild the new optimal search patterns and speed of
movements each time a foraging event on a patch, or set of patches, are
completed (Yang & Yao, 2005). This was a focus area in the OFT research
field in the late 1990s and 00s. The number of recent models proposed
using this approach are numerous (Branke, 2002; Jin & Branke, 2005;
Tin
´
os & Yang, 2005).



9

Evolutionary Foraging Algorithms (EA)

1.
Bacterial foraging algorithms (BFA) and Dynamic BFA
(DBFA)

2.
Group foraging theory and diversity in Evolutionary
algorithms

3.

Dynamic and Memory enhanced foraging algorithms (E. Coli)

4.
Thermodynamical Genetic Algorithm (TDGA)





10

Agenda

Introduction and Background

Optimal Foraging Theory (OFT)

Foraging Models

Economic perspective (EMH and REH)

Human Factors

Proposed Framework

Question and Answers


11

EMH and REH

1.
Efficient Market Hypothesis

2.
Rational Expectance Hypothesis

3.
Price Dispersion and 2
-
step models

12

Agenda

Introduction and Background

Optimal Foraging Theory (OFT)

Foraging Models

Economic perspective (EMH and REH)

Human Factors

Proposed Framework

Question and Answers


13

Human Factors

14

Agenda

Introduction and Background

Optimal Foraging Theory (OFT)

Foraging Models

Economic perspective (EMH and REH)

Human Factors

Proposed Framework

Question and Answers


15

Constructs

The task of the seller is to minimize the consumer surplus, while the task
of the consumer is to maximize it. It is important to note that if there are
no consumer surplus, the sale cannot occur (consumers would be
unwilling to proceed).

Therefore some consumer surplus has to exist, however marginal. In a
foraging model an implicit equilibrium should exists between the
consumer price, the foraging costs and the foraging surplus on one side
and the optimal (best price available) and the incremental foraging costs
of locating this best price.


16

Constructs

17

Time Constructs

18

Foraging Costs and Incremental Foraging Costs

19

Foraging Search Costs

20

Overall model (work in progress)

21

Example
-

calculations

22

Some hypothesis

23

Some hypothesis

24

Your Turn!

How to contact me:

Bjarne Berg

bergb@lr.edu