validity and reliability of cranfield-like evaluation in information retrieval
DESCRIPTION
TRANSCRIPT
Validity and Reliability of Cranfield-like Evaluation in Information Retrieval
Julián Urbano
Picture by Tom Parnell Glasgow, Scotland · September 2013
Talk outline
• Why we want to Evaluate…
• …and what we do with Cranfield
• Validity: users versus systems
• Reliablity: estimating from samples
Why we want to Evaluate
The two questions
• How good is my system? – What does good mean?
– What is good enough?
• Is system A better than system B? – What does better mean?
– How much better?
• Efficiency? Effectiveness? Ease?
Measure user experience
• Time to complete task
• Idle time
• Success rate
• Failure rate
• Frustration
• Ease to learn
• Ease to use
…and a long etcetera
We want to know some distributions
• For an arbitrary user, need and document collection, what is the distribution of:
• They describe user experience, fully
0 time to complete task
none frustration
much some
The big(ger) picture
• Different user-measures attempting to assess the same thing: user satisfaction
– How likely is it that an arbitrary user, with an arbitrary need (and with an arbitrary document collection) will be satisfied by the system?
• This is the ultimate goal: the good, the better
The big(ger) question
• User satisfaction…as Bernoulli trial
• Probability of satisfaction?
• Probability that k in n users are satisfied?
• Probability of >80% users satisfied?
satisfaction yes no
What we do with Cranfield
Sources of variability
user-measure = f(documents, need, user, system)
• Try to estimate the user-measure distribution
– Sample documents, needs and users
– Problematic
• Representativeness
• Cost
• Ethics
– Hard to replicate and repeat results
Fix samples
• Get a (hopefully) good sample and fix it
– Document collection
– Topic set
– A step towards reproducibility
• Still have to sample users, but can’t fix them!
– Very large source of variability
– Hard to replicate and repeat experiments
– Complex, costly, ethical issues
– Example: ASTIA-Uniterm studies
Simulate users…and fix them
• Cleverdon’s idea: remove users, but include a static user component, fixed across experiments
– The judgments in the ground truth
• Remove all sources of variability, except systems
user-measure = f(documents, need, user, system)
Simulate users…and fix them
• Cleverdon’s idea: remove users, but include a static user component, fixed across experiments
– The judgments in the ground truth
• Remove all sources of variability, except systems
user-measure = f(documents, need, user, system)
user-measure = f(system)
Test collections
user-measure = f(system)
• Test collections are tools to estimate distributions of user-measures
– Reproducibility becomes possible and easy
– Experiments are inexpensive (collections are not)
– Research becomes systematic
Wait a minute
• Are we estimating distributions about users or distributions about systems?
system-effectiveness = f(system, measure)
• We come up with different distributions of system-effectiveness, one per measure
• Each measure has its own assumptions
Assumption
• System-measures correspond to user-measures
Users Systems
Time to complete task Idle time
Success rate Failure rate Frustration
Ease to learn Ease to use Satisfaction
…
P AP RR DCG nDCG ERR GAP Q …
Assumption
• System-measures correspond to user-measures
Users Systems
Time to complete task Idle time
Success rate Failure rate Frustration
Ease to learn Ease to use Satisfaction
…
P AP RR DCG nDCG ERR GAP Q …
Assumption
• System-measures correspond to user-measures
Users Systems
Time to complete task Idle time
Success rate Failure rate Frustration
Ease to learn Ease to use Satisfaction
…
P AP RR DCG nDCG ERR GAP Q …
Assumption
• System-measures correspond to user-measures
Users Systems
Time to complete task Idle time
Success rate Failure rate Frustration
Ease to learn Ease to use Satisfaction
…
P AP RR DCG nDCG ERR GAP Q …
Assumption
• System-measures correspond to user-measures
Users Systems
Time to complete task Idle time
Success rate Failure rate Frustration
Ease to learn Ease to use Satisfaction
…
P AP RR DCG nDCG ERR GAP Q …
Assumption
• Well, at least we assume the correlation
– Are they correlated? How well?
• Test collections: estimators of user distributions
– What we want to measure: user satisfaction
– What we do measure: system effectiveness
Validity and Reliability
• Validity: are we measuring what we want to?
– External validity: Are topics, documents and assessors representative?
– Construct validity: Do system-measures correspond to user-measures?
– Conclusion validity: Is system A really better than system B?
• Reliability: how repeatable are the results?
– How large do collections have to be to ensure repeatability with a different sample?
Validity
Assumption
• Systems with better effectiveness are perceived by users as more useful, more satisfactory
• Tricky: different effectiveness measures and relevance scales give different results
– Which one is better to predict satisfaction?
• The goal is user satisfaction, not system effectiveness
Mapping
• Try to map system effectiveness onto user satisfaction, experimentally
• If P@10 = 0.2, how likely is it that the user will find the results satisfactory?
• What if DCG@20 = 0.467?
• What if ERR = 0.9?
User-oriented System-measures
• Effectiveness measures are generally not formulated to correlate with user-satisfaction
• If effectiveness is 0, we expect 0% probability of user satisfaction
• If effectiveness is 1, we expect 100% probability
• If effectiveness is 𝜆, we expect 100𝜆%
• But this is not what we have
Unbounded measures
𝐷𝐶𝐺@𝑘 = 𝑔𝑎𝑖𝑛 𝑟𝑖
𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡 𝑖
𝑘
𝑖=1
• Upper bound depends on cutoff, gain function and relevance scale
– Normalize effectiveness between 0 and 1
– What is the best we can do with 𝑘 documents?
𝐷𝐶𝐺@𝑘 = 𝑔𝑎𝑖𝑛 𝑟𝑖 𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡 𝑖
𝑔𝑎𝑖𝑛 𝑟𝑖∗ 𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡 𝑖
𝑘
𝑖=1
Recall-oriented measures
𝐴𝑃@𝑘 =1
ℛ1 𝑟i · 𝑃@𝑖
𝑘
𝑖=1
• 𝐴𝑃@𝑘 = 1 only possible if 𝑘 ≥ ℛ1
• Reformulate towards users
– What is the best we can do with 𝑘 documents, regardless of the judgments in the ground truth?
𝐴𝑃@𝑘 =1
𝑘 𝑟𝐴𝑖 · 𝑃@𝑖
𝑘
𝑖=1
Ideal ranking
𝑛𝐷𝐶𝐺@𝑘 = 𝑔𝑎𝑖𝑛 𝑟𝑖 𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡 𝑖 𝑘𝑖=1
𝑔𝑎𝑖𝑛 𝑖𝑑𝑒𝑎𝑙𝑖 𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡 𝑖 𝑘𝑖=1
• If there is only one relevant, 𝑛𝐷𝐶𝐺@10 = 1 even if we retrieve nine nonrelevants
• Assume the ideal ranking has only excellent documents, with maximum relevance
𝑛𝐷𝐶𝐺@𝑘 = 𝑔𝑎𝑖𝑛 𝑟𝑖 𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡 𝑖 𝑘𝑖=1
𝑔𝑎𝑖𝑛 𝑟𝑖∗ 𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡 𝑖 𝑘
𝑖=1
• This is basically user-oriented 𝐷𝐶𝐺@𝑘
Audio Music Similarity
• Song as input to system, audio signal
• Retrieve songs musically similar to it, by content
• Resembles traditional Ad Hoc retrieval in Text IR
• (most?) Important task in Music IR
– Music recommendation
– Playlist generation
– Plagiarism detection
Measures
• All reformulated, user-oriented
– What is the best we can do under the user model?
• Binary
– P, AP, RR
• Graded
– CG, DCG, Q, RBP, ERR, GAP, ADR , EDCG
– Linear and exponential gains
Relevance scales
• Originally used
– Broad: 3 levels
– Fine: 101 levels
• Artificially made from the Fine scale
– Graded with 3, 4 and 5 levels, evenly spaced
– Binary, with threshold equal 20, 40, 60 and 80
Measures and Scales
Measure Original Artificial Graded Artificial Binary
Broad Fine 𝑛ℒ = 3 𝑛ℒ = 4 𝑛ℒ = 5 ℓ𝑚𝑖𝑛 = 20 ℓ𝑚𝑖𝑛 = 40 ℓ𝑚𝑖𝑛 = 60 ℓ𝑚𝑖𝑛 = 80
𝑃@5 x x x x
𝐴𝑃@5 x x x x
𝑅𝑅@5 x x x x
𝐶𝐺𝑙@5 x x x x x 𝑃@5 𝑃@5 𝑃@5 𝑃@5
𝐶𝐺𝑒@5 x x x x 𝑃@5 𝑃@5 𝑃@5 𝑃@5
𝐷𝐶𝐺𝑙@5 x x x x x x x x x
𝐷𝐶𝐺𝑒@5 x x x x 𝐷𝐶𝐺𝑙@5 𝐷𝐶𝐺𝑙@5 𝐷𝐶𝐺𝑙@5 𝐷𝐶𝐺𝑙@5
𝐸𝐷𝐶𝐺𝑙@5 x x x x x x x x x
𝐸𝐷𝐶𝐺𝑒@5 x x x x 𝐸𝐷𝐶𝐺𝑙@5 𝐸𝐷𝐶𝐺𝑙@5 𝐸𝐷𝐶𝐺𝑙@5 𝐸𝐷𝐶𝐺𝑙@5
𝑄𝑙@5 x x x x x 𝐴𝑃@5 𝐴𝑃@5 𝐴𝑃@5 𝐴𝑃@5
𝑄𝑒@5 x x x x 𝐴𝑃@5 𝐴𝑃@5 𝐴𝑃@5 𝐴𝑃@5
𝑅𝐵𝑃𝑙@5 x x x x x x x x x
𝑅𝐵𝑃𝑒@5 x x x x 𝑅𝐵𝑃𝑙@5 𝑅𝐵𝑃𝑙@5 𝑅𝐵𝑃𝑙@5 𝑅𝐵𝑃𝑙@5
𝐸𝑅𝑅𝑙@5 x x x x x x x x x
𝐸𝑅𝑅𝑒@5 x x x x 𝐸𝑅𝑅𝑙@5 𝐸𝑅𝑅𝑙@5 𝐸𝑅𝑅𝑙@5 𝐸𝑅𝑅𝑙@5
𝐺𝐴𝑃@5 x x x x x 𝐴𝑃@5 𝐴𝑃@5 𝐴𝑃@5 𝐴𝑃@5
𝐴𝐷𝑅@5 x x x x x x x x
Experimental Design
Experimental Design
user preference (agrees or disagrees with effectiveness)
Experimental Design
non-preference (can’t decide)
What can we infer?
• Preference: difference noticed by user
– Positive: user agrees with evaluation
– Negative: user disagrees with evaluation
• Non-preference: difference not noticed by user
– Good: both systems are satisfactory
– Bad: both systems are not satisfactory
Data
• Queries, documents and judgments from MIREX
– MIREX: TREC-like evaluation forum in Music IR
• 4,115 unique and artificial examples
– Covering full range of effectiveness
• In 10 bins 0, 0.1 , 0.1, 0.2 ,… , [0.9, 1]
– At least 200 examples per measure/scale/bin
• 432 unique queries, 5,636 unique documents
Collecting User Preferences
• Crowdsourcing
– Quality control through trap examples
• Total: 547 unique subjects, 11,042 preferences
• Accepted: 175 subjects, 9,373 preferences
• After trap questions: 113 subjects
Single system: how good is it?
• 2,045 non-preferences (49%)
– 1,056 satisfactory
– 969 non-satisfactory
What do we expect?
Single system: how good is it?
• 2,045 non-preferences (49%)
– 1,056 satisfactory
– 969 non-satisfactory
Linear mapping
Single system: how good is it?
Large thresholds
underestimate satisfaction
Single system: how good is it?
Ranking does not affect
satisfaction?
Single system: how good is it?
Exponential gain
underestimates satisfaction
Single system: how good is it?
• Best adhere to the diagonal
– 𝐶𝐺𝑙@5, 𝐷𝐶𝐺𝑙@5 and 𝑅𝐵𝑃𝑙@5
– Not necessarily better: just easier to interpret
• About 20% bias at endpoints
– Room for improvement with personalization
• Less sensitive to subjectivity in relevance
– Minimize 𝑃(𝑆𝑎𝑡│0) and maximize 𝑃(𝑆𝑎𝑡│1)
– ℓ𝑚𝑖𝑛 = 40 and 𝐵𝑟𝑜𝑎𝑑 behave better
– 𝐶𝐺@5, 𝐷𝐶𝐺@5, 𝑅𝐵𝑃@5 and 𝐺𝐴𝑃@5
Two systems: which one is better?
• 2,090 preferences (51%)
– 1,019 for system A
– 1,071 for system B
What do we expect?
Two systems: which one is better?
• 2,090 preferences (51%)
– 1,019 for system A
– 1,071 for system B
Users always notice the difference… …regardless
of how large it is
Two systems: which one is better?
Need quite large
differences!
Two systems: which one is better?
More relevance levels better to discriminate
Two systems: which one is better?
Bad correlation?
Two systems: which one is better?
• Users prefer the (supposedly) worse system
User Agrees with Evaluation
• Closer to ideal 𝑃 𝐴𝑔𝑔 = 1 Δ𝜆 = 1
– ℓ𝑚𝑖𝑛 = 80 better among binaries
– 𝐹𝑖𝑛𝑒 better for linear gain
– 𝑛ℒ = 5 better for exponential gain
– 𝐶𝐺@5, 𝐷𝐶𝐺@5, 𝑅𝐵𝑃@5 and 𝐺𝐴𝑃@5
User Disagrees with Evaluation
• Closer to ideal 𝑃 𝐴𝑔𝑔 = −1 Δ𝜆 = 0
– ℓ𝑚𝑖𝑛 = 40 better among binaries
– 𝐹𝑖𝑛𝑒 better for linear gain
– 𝐵𝑟𝑜𝑎𝑑 better with exponential gain
– 𝐶𝐺@5, 𝐺𝐴𝑃@5, 𝐷𝐶𝐺@5 and 𝑅𝐵𝑃@5
Summary
• Linear gain better than exponential gain
– Except, slightly, in terms of disagreements
• Measures oriented to a single document are not appropriate for a music recommendation setting
• Gain is independent of other documents
• 𝐵𝑟𝑜𝑎𝑑 better to predict satisfaction
• 𝐹𝑖𝑛𝑒 better to predict user agreement
• Binary scales worst overall
Summary
• We can map system effectiveness onto probability of user satisfaction
• ~20% of users disagree with effectiveness
– Practical upper (and lower) bound in evaluation
– Need to incorporate user profiles
• Somehow included in MSD Challenge
• Δ𝜆 ≈ 0.4 needed for users to agree
– Historically observed only 20% of times in MIREX
– Be careful with statistical significance!
Satisfaction over samples
User Satisfaction
• So far only for a query and a user (Bernoulli)
– 𝑃 𝑆𝑎𝑡 𝜆𝑞
• Easily for 𝑛 users (Binomial)
– 𝑃 𝑆𝑎𝑡𝑛 = 𝑘 𝜆𝑞
• Example: 𝑄𝑙@5 = 0.61
– 𝑃 𝑆𝑎𝑡 ≈ 0.7
– 𝑃 𝑆𝑎𝑡15 = 10 ≈ 0.21
• What about a sample of queries 𝒬?
User Satisfaction over a Sample
𝐸 𝑃 𝑆𝑎𝑡 =1
𝑛𝒬 𝑃 𝑆𝑎𝑡 𝜆𝑞𝑞∈𝒬
• Example: satisfaction is underestimated
System Success
• If 𝑃 𝑆𝑎𝑡 ≥ 𝑡𝑟𝑒𝑠𝑜𝑙𝑑 the system is successful
• If we want the majority of users to be satisfied
– 𝑃 𝑆𝑢𝑐𝑐 = 1 − F 𝑃 𝑆𝑎𝑡 0.5
• Intuition: improving bad queries is worthier than further improving good ones
System Success
• Example:
– 𝐸 Δ𝜆 = −0.0021
System Success
• Example:
– 𝐸 Δ𝜆 = −0.0021
– 𝐸 𝛥𝑃 𝑆𝑎𝑡 = 0.0011
System Success
• Example:
– 𝐸 Δ𝜆 = −0.0021
– 𝐸 𝛥𝑃 𝑆𝑎𝑡 = 0.0011
– 𝐸 Δ𝑃 𝑆𝑢𝑐𝑐 = 0.07
Summary
• Need to consider full distributions
– Always average or good on average?
• Modeling full distribution
– Normal for small query sets, Empirical for large
– Beta always better for 𝐹𝑖𝑛𝑒 scale
Summary
• Intuitive interpretations of effectiveness fail
– Contradictory results in terms of user satisfaction
Reliability
Samples
• Test collections are samples from larger, possibly infinite, populations
– Documents, queries and users
• Δ𝜆 is just an estimate of the population mean 𝜇Δ𝜆
• How reliable is our conclusion?
Reliability vs Cost
• Building reliable collections is easy
• Just use more documents, queries and assessors
• But it is prohibitively expensive
• Best option is to increase query set size
– Largest source of variability
• How many queries?
– First we need to measure reliability
Data-based approach
1. Randomly split query set
2. Compute indicators of reliability based on these two query subsets
3. Extrapolate to larger query sets
…with some variations
Data-based reliability indicators
• Compare results with two collections
– Kendall tau correlation
– AP correlation
– Absolute sensitivity
– Relative sensitivity
– Power ratio
– Minor conflict ratio
– Major conflict ratio
– RMSE
Generalizability Theory approach
• Address variability of scores, not just means
• G-study
– Estimate variance components from previous, representative data
– Usually previous test collections
• D-study
– Estimate reliability based on estimated variance components from G-study
G-study
𝜎2 = 𝜎𝑠
2 + 𝜎𝑞2 + 𝜎𝑠:𝑞
2
• Estimated with Analysis of Variance
G-study
𝜎2 = 𝜎𝑠
2 + 𝜎𝑞2 + 𝜎𝑠:𝑞
2
• Estimated with Analysis of Variance
system differences,
our goal!
G-study
𝜎2 = 𝜎𝑠
2 + 𝜎𝑞2 + 𝜎𝑠:𝑞
2
• Estimated with Analysis of Variance
system differences,
our goal! query difficulty
G-study
𝜎2 = 𝜎𝑠
2 + 𝜎𝑞2 + 𝜎𝑠:𝑞
2
• Estimated with Analysis of Variance
system differences,
our goal! query difficulty
some systems better for
some queries
D-study
• Relative stability: 𝐸𝜌2 =𝜎𝑠2
𝜎𝑠2+
𝜎𝑠:𝑞2
𝑛𝑞′
• Absolute stability: Φ =𝜎𝑠2
𝜎𝑠2+
𝜎𝑞2+𝜎𝑠:𝑞
2
𝑛𝑞′
• Easy to estimate how many queries we need to reach a certain stability level (1MQ track) – ≈80 queries sufficient for stable rankings
– ≈130 queries for stable absolute scores
G-Theory approach
• How sensitive is the D-study to the initial data used in the G-study?
• How should we interpret G-Theory indicators in practice? What does 𝐸𝜌2 = 0.95 mean?
• From the above, review reliability of over 40 TREC test collections
Data
• 43 TREC collections
– From TREC 3 to TREC 2011
• 12 tasks across 10 tracks
– Ad hoc, Web, Novelty, Genomics, Robust, Terabyte, Enterprise, Million Query, Medical and Microblog
Sensitivity: experiment
• Vary number of queries in G-study – From 𝑛𝑞 = 5 to full set
– Use all runs available
• Run D-study – Compute 𝐸𝜌 2 and Φ
– Compute 𝑛 𝑞′ to reach 0.95 stability
• 200 random trials
Variability due to queries
We may get 𝐸𝜌 2 = 0.9 or 𝐸𝜌 2 = 0.3, depending on what 10 queries we use
Variability due to queries
Sensitivity: experiment
• Do the same, but vary number of systems
– From 𝑛𝑠 = 5 to full set
– Use all queries available
• 200 random trials
Variability due to systems
We may get 𝐸𝜌 2 = 0.9 or 𝐸𝜌 2 = 0.5, depending on what 20 systems we use
Variability due to systems
Results
• G-Theory is very sensitive to initial data – Need about 50 queries and 50 systems for differences
in 𝐸𝜌 2 and Φ below 0.1
• Number of queries for 𝐸𝜌 2 = 0.95 may change in orders of magnitude – Microblog2011 (all 184 systems and 30 queries) • Need 63 to 133 queries
– Medical2011 (all 34 queries and 40 systems) • Need 109 to 566 queries
Compute confidence intervals
Compute confidence intervals
Account for variability in initial data
Compute confidence intervals
Required number of queries to reach the
lower end of the interval
Compute confidence intervals
Summary in TREC
• 𝐸𝜌 2: mean=0.88 sd=0.1
– 95% conf. intervals are 0.1 long
• Φ : mean=0.74 sd=0.2
– 95% conf. intervals are 0.19 long
Interpretation: experiment
• Split query set in 2 subsets
– From 𝑛𝑞 = 10 to full set / 2
– Use all runs available
• Run D-study
– Compute 𝐸𝜌 2 and Φ and map onto 𝜏, sensitivity, power, conflicts, etc.
• 50 random trials
– Over 28,000 datapoints
*All mappings in the paper
Example: 𝑬𝝆𝟐 → 𝝉
𝐸𝜌2 = 0.95 → 𝜏 ≈ 0.85
*All mappings in the paper
Example: 𝑬𝝆𝟐 → 𝝉
𝜏 = 0.9 → 𝐸𝜌2 ≈ 0.97
*All mappings in the paper
Example: 𝑬𝝆𝟐 → 𝝉
Million Query 2007
Million Query 2008
*All mappings in the paper
Example: 𝑬𝝆𝟐 → 𝝉
Future predictions
• This allows us to make more informed decisions within a collection
• What about a new collection?
– Fit a single model for each mapping with 90% and 95% prediction intervals
• Assess whether a larger collection is really worth the effort
*All mappings in the paper
Example: 𝑬𝝆𝟐 → 𝝉
current collection
*All mappings in the paper
Example: 𝑬𝝆𝟐 → 𝝉
current collection target
*All mappings in the paper
Example: 𝑬𝝆𝟐 → 𝝉
Example: 𝚽→ 𝒓𝒆𝒍. 𝒔𝒆𝒏𝒔𝒊𝒕𝒗𝒊𝒕𝒚
Example: 𝚽→ 𝒓𝒆𝒍. 𝒔𝒆𝒏𝒔𝒊𝒕𝒗𝒊𝒕𝒚
Summary
• G-Theory is regarded as more appropriate, ease to use and powerful to assess reliability than the traditional data-based approaches
• But it is quite sensitive to initial data used to estimate variance components
– Data-based approaches are too!
• and almost impossible to interpret in practice
Summary
• Need about 50 queries and 50 systems to have robust estimates of reliability
– That is a whole collection already!
– Need to use confidence intervals
• Previous interpretation overestimated reliability
– 𝜏 = 0.9 → 𝐸𝜌2 ≈ 0.97
– 𝐸𝜌2 = 0.95 → 𝜏 ≈ 0.85
Reliability: review of TREC collections
Outline
• Estimate 𝐸𝜌 2 and Φ , with 95% confidence intervals, and full query set
• Map onto 𝜏, sensitivity, power, conflicts, etc.
• Results within tasks offer a historical perspective on reliability since 1994
*All collections and mappings in the paper
Example: Ad hoc 3-8
• 𝐸𝜌 2 ∈ 0.86,0.93 → 𝜏 ∈ [0.65,0.81]
• 𝑚𝑖𝑛𝑜𝑟 𝑐𝑜𝑛𝑓𝑙𝑖𝑐𝑡𝑠 ∈ 0.6, 8.2 %
• 𝑚𝑎𝑗𝑜𝑟 𝑐𝑜𝑛𝑓𝑙𝑖𝑐𝑡𝑠 ∈ 0.02, 1.38 %
• Queries to get 𝐸𝜌2 = 0.95: [37,233]
• Queries to get Φ = 0.95: [116,999]
• 50 queries were used
Example: Web ad hoc
• TREC-8 to TREC-2001: WT2g and WT10g
– 𝐸𝜌 2 ∈ 0.86,0.93 → 𝜏 ∈ [0.65,0.81]
– Queries to get 𝐸𝜌2 = 0.95: 40,220
• TREC-2009 to TREC-2011: ClueWeb09
– 𝐸𝜌 2 ∈ 0.8,0.83 → 𝜏 ∈ [0.53,0.59]
– Queries to get 𝐸𝜌2 = 0.95: 107,438
• 50 queries were used
Historical trend
• Decreasing within and across tracks?
Historical trend
• Systems getting better for specific problems?
Historical trend
• Increasing task-specificity in queries?
Historical reliability in TREC
• On average, 𝐸𝜌2 = 0.88 → 𝜏 ≈ 0.7
• Some collections clearly unreliable
– Web Distillation 2003, Genomics 2005, Terabyte 2006, Enterprise 2008, Medical 2011 and Web Ad Hoc 2011
• 50 queries not enough for stable rankings, about 200 are needed in most cases
Implications
• Fixing a minimum number of queries across tracks is unrealistic
– Not even across editions of the same task
• Need to analyze on a case-by-case basis, while building the collections
– GT4IReval, R package online
Current and future work
Validity
• Similar studies in Text IR to map effectiveness onto user satisfaction
• Particularly interesting because there are several query types, and users behave differently – Single measure to use in all cases?
– Use different measures and average them all?
• Further user studies to figure out what makes users say good and better
• How should test collections be extended to incorporate more user information?
Reliability
• Study assessor effect
• Study document collection effect
• Better models to map G-theory indicators onto understandable data-based indicators
• Methods to reliably measure reliability while building the collection
References
General
• Cleverdon, C. W. (1991). The Significance of the Cranfield Tests on Index Languages. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 3–12).
• Sanderson, M. (2010). Test Collection Based Evaluation of Information Retrieval Systems. Foundations and Trends in Information Retrieval, 4(4), 247–375.
• Robertson, S. (2008). On the History of Evaluation in IR. Journal of Information Science, 34(4), 439–456. • Harman, D. K. (2011). Information Retrieval Evaluation. Synthesis Lectures on Information Concepts, Retrieval,
and Services, 3(2), 1–119. • Voorhees, E. M. (2002). The Philosophy of Information Retrieval Evaluation. In Workshop of the Cross-Language
Evaluation Forum (pp. 355–370). • Tague-Sutcliffe, J. (1992). The Pragmatics of Information Retrieval Experimentation, Revisited. Information
Processing and Management, 28(4), 467–490. • Gull, C. D. (1956). Seven Years of Work on the Organisation of Materials in a Special Library. American
Documentation, 7(4), 320–329. • Urbano, J., Schedl, M., & Serra, X. (2013). Evaluation in Music Information Retrieval. Journal of Intelligent
Information Systems. • Urbano, J. (2013). Evaluation in Audio Music Similarity. PhD dissertation, University Carlos III of Madrid. • Trochim, W. M. K., & Donnelly, J. P. (2007). The Research Methods Knowledge Base (3rd ed.). Atomic Dog
Publishing. • Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and Quasi-Experimental Designs for
Generalized Causal Inference. Houghton-Mifflin. • Zobel, J., Webber, W., Sanderson, M., & Moffat, A. (2011). Principles for Robust Evaluation Infrastructure. In ACM
CIKM Workshop on Data infrastructures for Supporting Information Retrieval Evaluation.
Validity
• Allan, J., Carterette, B., & Lewis, J. (2005). When Will Information Retrieval Be “Good Enough”? In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 433–440).
• Al-Maskari, A., Sanderson, M., & Clough, P. (2007). The Relationship between IR Effectiveness Measures and User Satisfaction. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 773–774).
• Al-Maskari, A., Sanderson, M., Clough, P., & Airio, E. (2008). The Good and the Bad System: Does the Test Collection Predict User’s Effectiveness. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 59–66).
• Bailey, P., Craswell, N., Soboroff, I., Thomas, P., Vries, A. P. de, & Yilmaz, E. (2008). Relevance Assessment: Are Judges Exchangeable and Does it Matter? In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 667–674).
• Bennett, P. N., Carterette, B., Chapelle, O., & Joachims, T. (2008). Beyond Binary Relevance: Preferences, Diversity and Set-Level Judgments. ACM SIGIR Forum, 42(2), 53–58.
• Carterette, B. (2011). System Effectiveness, User Models, and User Utility: A General Framework for Investigation. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 903–912).
• Carterette, B., Bennett, P. N., Chickering, D. M., & Dumais, S. T. (2008). Here or There: Preference Judgments for Relevance. In European Conference on Information Retrieval (pp. 16–27).
• Carterette, B., & Soboroff, I. (2010). The Effect of Assessor Error on IR System Evaluation. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 539–546).
• Hersh, W., Turpin, A., Price, S., Chan, B., Kraemer, D., Sacherek, L., & Olson, D. (2000). Do Batch and User Evaluations Give the Same Results? In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 17–24).
Validity
• Hersh, W., Turpin, A., Sacherek, L., Olson, D., Price, S., Chan, B., & Kraemer, D. (2000). Further Analysis of Whether Batch and User Evaluations Give the Same Results With a Question-Answering Task. In Text REtrieval Conference.
• Hu, X., & Kando, N. (2012). User-Centered Measures vs. System Effectiveness in Finding Similar Songs. In International Society for Music Information Retrieval Conference (pp. 331–336).
• Huffman, S. B., & Hochster, M. (2007). How Well does Result Relevance Predict Session Satisfaction? In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 567–573).
• Ingwersen, P., & Järvelin, K. (2005). The Turn: Integration of Information Seeking and Retrieval in Context. Springer.
• Järvelin, K. (2011). IR Research: Systems, Interaction, Evaluation and Theories. ACM SIGIR Forum, 45(2), 17–31. • Mizzaro, S. (1997). Relevance: The Whole History. Journal of the American Society for Information Science, 48(9),
810–832. • Sanderson, M., Paramita, M. L., Clough, P., & Kanoulas, E. (2010). Do User Preferences and Evaluation Measures
Line Up? In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 555–562).
• Schedl, M., Flexer, A., & Urbano, J. (2013). The Neglected User in Music Information Retrieval Research. Journal of Intelligent Information Systems.
• Schedl, M., Stober, S., Gómez, E., Orio, N., & Liem, C. C. S. (2012). User-Aware Music Retrieval. In M. Müller, M. Goto, & M. Schedl (Eds.), Multimodal Music Processing (pp. 135–156). Dagstuhl Publishing.
• Scholer, F., & Turpin, A. (2008). Relevance Thresholds in System Evaluations. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 693–694).
Validity
• Smucker, M. D., & Clarke, C. L. A. (2012). The Fault, Dear Researchers, is Not in Cranfield, But in Our Metrics, that They Are Unrealistic. In European Workshop on Human-Computer Interaction and Information Retrieval (pp. 11–12).
• Thom, J. A., & Scholer, F. (2007). A Comparison of Evaluation Measures Given How Users Perform on Search Tasks. In Australasian Document Computing Symposium (pp. 100–103).
• Turpin, A., & Hersh, W. (2001). Why Batch and User Evaluations Do Not Give the Same Results. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 225–231).
• Turpin, A., & Hersh, W. (2002). User Interface Effects in Past Batch Versus User Experiments. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 431–432).
• Turpin, A., & Scholer, F. (2006). User Performance Versus Precision Measures for Simple Search Tasks. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 11–18).
• Urbano, J., Downie, J. S., Mcfee, B., & Schedl, M. (2012). How Significant is Statistically Significant? The case of Audio Music Similarity and Retrieval. In International Society for Music Information Retrieval Conference (pp. 181–186).
Reliability
• Allan, J., Aslam, J. A., Carterette, B., Pavlu, V., & Kanoulas, E. (2008). Million Query Track 2008 Overview. In Text REtrieval Conference.
• Allan, J., Carterette, B., Aslam, J. A., Pavlu, V., Dachev, B., & Kanoulas, E. (2007). Million Query Track 2007 Overview. In Text REtrieval Conference.
• Armstrong, T. G., Moffat, A., Webber, W., & Zobel, J. (2009). Improvements that Don’t Add Up: Ad-Hoc Retrieval Results since 1998. In ACM International Conference on Information and Knowledge Management (pp. 601–610).
• Banks, D., Over, P., & Zhang, N.-F. (1999). Blind Men and Elephants: Six Approaches to TREC data. Information Retrieval, 1(1-2), 7–34.
• Bodoff, D. (2008). Test Theory for Evaluating Reliability of IR Test Collections. Information Processing and Management, 44(3), 1117–1145.
• Bodoff, D., & Li, P. (2007). Test Theory for Assessing IR Test Collections. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 367–374).
• Brennan, R. L. (2001). Generalizability Theory. Springer. • Buckley, C., & Voorhees, E. M. (2000). Evaluating Evaluation Measure Stability. In International ACM SIGIR
Conference on Research and Development in Information Retrieval (pp. 33–34). • Carterette, B., Pavlu, V., Fang, H., & Kanoulas, E. (2009). Million Query Track 2009 Overview. In Text REtrieval
Conference. • Carterette, B., Pavlu, V., Kanoulas, E., Aslam, J. A., & Allan, J. (2008). Evaluation Over Thousands of Queries. In
International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 651–658). • Carterette, B., Pavlu, V., Kanoulas, E., Aslam, J. A., & Allan, J. (2009). If I Had a Million Queries. In European
Conference on Information Retrieval (pp. 288–300). • Lin, W.-H., & Hauptmann, A. (2005). Revisiting the Effect of Topic Set Size on Retrieval Error. In International ACM
SIGIR Conference on Research and Development in Information Retrieval (pp. 637–638).
Reliability
• Cormack, G. V., & Lynam, T. R. (2006). Statistical Precision of Information Retrieval Evaluation. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 533–540).
• Robertson, S., & Kanoulas, E. (2012). On Per-Topic Variance in IR Evaluation. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 891–900).
• Sakai, T. (2007). On the Reliability of Information Retrieval Metrics Based on Graded Relevance. Information Processing and Management, 43(2), 531–548.
• Sanderson, M., & Zobel, J. (2005). Information Retrieval System Evaluation: Effort, Sensitivity, and Reliability. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 162–169).
• Sanderson, M., Turpin, A., Zhang, Y., & Scholer, F. (2012). Differences in Effectiveness Across Sub-collections. In ACM International Conference on Information and Knowledge Management (pp. 1965–1969).
• Shavelson, R. J., & Webb, N. M. (1991). Generalizability Theory: A Primer. Sage Publications. • Smucker, M. D., Allan, J., & Carterette, B. (2007). A Comparison of Statistical Significance Tests for Information
Retrieval Evaluation. In ACM International Conference on Information and Knowledge Management (pp. 623–632).
• Urbano, J., Marrero, M., & Martín, D. (2013). A Comparison of the Optimality of Statistical Significance Tests for Information Retrieval Evaluation. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 925–928).
• Urbano, J., Marrero, M., & Martín, D. (2013). On the Measurement of Test Collection Reliability. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 393–402).
• Voorhees, E. M. (2000). Variations in Relevance Judgments and the Measurement of Retrieval Effectiveness. Information Processing and Management, 36(5), 697–716.
• Voorhees, E. M. (2009). Topic Set Size Redux. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 806–807).
Reliability
• Voorhees, E. M., & Buckley, C. (2002). The Effect of Topic Set Size on Retrieval Experiment Error. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 316–323).
• Webber, W., Moffat, A., & Zobel, J. (2008). Statistical Power in Retrieval Experimentation. In ACM International Conference on Information and Knowledge Management (pp. 571–580).
• Yilmaz, E., Aslam, J. A., & Robertson, S. (2008). A New Rank Correlation Coefficient for Information Retrieval. In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 587–594).
• Zobel, J. (1998). How Reliable are the Results of Large-Scale Information Retrieval Experiments? In International ACM SIGIR Conference on Research and Development in Information Retrieval (pp. 307–314).