Kia ora, thanks for your interest in how we calculate an experience's ranking score. It's at the core of Rankers so I'm pleased you're curious.

The ranking score percentage is used to compare and sort experiences in ranking tables. It is not necessarily a direct measurement of the quality of a particular experience as rated by its customers. I've found it a useful tool to allow me to find the best experiences with confidence. But I've also found it important to read the customer reviews before making any final judgements!

We calculate an experience's ranking score using a multi-factor data model instead of a raw data average (mean). This model takes into account several important questions. For instance - is there a trusted body of reviews? What is the age of a review and is the review from a credible source?

Below you'll find details around some of the important factors that went into calculating the ranking score for Interislander Ferry.

If you have any questions or comments about our ranking score calculation please get in touch at info@rankers.co.nz. We don't believe this is perfect or complete so we're always interested in ways we might make improvements.

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Cymen Crick's avatar

Cymen Crick

Rankers Owner

Interislander Ferry

Valid Reviews

348 Valid Reviews

The Interislander Ferry experience has a total of 358 reviews. There are 348 valid reviews that are included when calculating the ranking score and 10 invalid reviews that are excluded from the calculation. Reviews can be excluded only when a reviewer is not verified or after an investigation by our team determines the reviewer is not genuine.

Below is the distribution of ratings for the 348 valid reviews:

Rating Count Percentage
10/10 40
11%
9/10 80
23%
8/10 103
30%
7/10 62
18%
6/10 29
8%
5/10 16
5%
4/10 7
2%
3/10 5
1%
2/10 2
1%
1/10 4
1%

77.10% Average

The raw data average (mean) for all the Interislander Ferry valid reviews is 77.10% and is based on 348 valid reviews. This value is not used to calculate the ranking score and it only provided here as a comparison to the weighted average.

Face-to-Face Reviews

309 Face-to-Face Reviews

The Rankers team meets with travellers while they’re in New Zealand and conducts face-to-face surveys. These reviews, in our opinion, are the most trusted in the industry and represent a critical control sample. To our knowledge, we are the only travel review website in the world that has gone to this extent.

More about face-to-face reviews

Within the 348 valid reviews, the experience has 309 face-to-face reviews collected during interviews by our team.

Below is the distribution of ratings for the 309 face-to-face reviews:

Rating Count Percentage
10/10 30
10%
9/10 70
23%
8/10 98
32%
7/10 58
19%
6/10 25
8%
5/10 15
5%
4/10 6
2%
3/10 4
1%
2/10 2
1%
1/10 1
0%

77.22% Average

The raw data average (mean) for all the Interislander Ferry face-to-face reviews is 77.22% and is based on 309 face-to-face reviews. This value is not used to calculate the ranking score and it only provided here for comparison purposes.

Weighted Average

71.28%

Rankers calculates a weighted mean as a base average on which we can improve. Individual review's ratings are given a weight based on several factors. The weight of a review determines the overall impact it'll have on the final weighted average.

Recent reviews have more weight as they are more relevant and reflect the experience as it currently operates. Over time reviews become less relevant and loose their impact on the ranking score.

Low rating reviews carry slightly less weight. This dampens the effect of very low ratings for every experience across the board. This is especially important when the experience has few reviews overall and a single negative rating can grossly mischaracterise an experience. Consistent poor reviews will still result in the experience receiving a comparitively low ranking score.

Credible sources provide reviews that can be trusted. If we have verified a reviewer is genuine via a face-to-face meeting then the review carries additional weight.

Reviewer Rating Age Relative Weight
edm 1/10 85 days 41%
Colin Barrow 9/10 146 days 100%
Pauline 6/10 299 days 84%
Megan 5/10 451 days 69%
Marjolaine Loitz 4/10 481 days 58%
Keli Knox 10/10 816 days 63%
Yar 1/10 1030 days 17%
Pinocity 6/10 1395 days 14%
Helen Russell 10/10 1576 days 9%
NewZealander 10/10 1850 days 5%
Tommy Pickett 9/10 2673 days 3%
Tom Bennett 8/10 2677 days 3%
Jeny Smolders 9/10 2679 days 3%
Gregg Wagstaff 7/10 2904 days 3%
Lianne Ijlst 8/10 2932 days 3%
Samantha and Neis 8/10 2933 days 3%
Brandon Cassidy 7/10 2949 days 3%
Vic Baughen 9/10 2951 days 3%
Anders Frank 7/10 2955 days 3%
Dina Schurer 8/10 2956 days 3%
Kim Youngsub 9/10 2957 days 3%
DEBBIE LAMBERT 10/10 2961 days 3%
Gary Williams 8/10 2961 days 3%
Kimberley Gardien 8/10 2968 days 3%
Antoine 9/10 2989 days 3%
Judit Van lanen 9/10 2994 days 3%
Bjorn Nielsen 8/10 2996 days 3%
Joel Virtanen 9/10 2998 days 3%
Corbin Hure 7/10 2998 days 3%
Ron 6/10 3001 days 2%
Thomas Simeon 8/10 3001 days 3%
Suzannah Hill 8/10 3002 days 3%
Kallan Mrozek 9/10 3003 days 3%
Kees Mol 9/10 3007 days 3%
Kristal Lavender 10/10 3007 days 3%
Bastian Bley 9/10 3008 days 3%
Jasmine Rogers 3/10 3009 days 1%
Louis Nilsson 8/10 3013 days 3%
Tim 7/10 3013 days 3%
Jendrik 6/10 3013 days 2%
Katharina 7/10 3014 days 3%
Chris Valchero 9/10 3017 days 3%
Rulp Niet 8/10 3019 days 3%
Soeren Buchheister 9/10 3020 days 3%
Chas Bronson 8/10 3020 days 3%
Jakob Lovdahl 9/10 3022 days 3%
Alexandra Schmidt 10/10 3032 days 3%
Jade Williams 10/10 3033 days 3%
Sam Staines 10/10 3034 days 3%
Nickolas Jonkergouw 7/10 3038 days 2%
Kirsty Smith 10/10 3038 days 3%
Eva Hesse 10/10 3053 days 3%
celine gries 8/10 3053 days 3%
tinagermany111 8/10 3067 days 3%
Cassandra Geyer 8/10 3252 days 2%
Olivier Reculeau 8/10 3253 days 2%
Thomas Michel 5/10 3254 days 2%
Lisa Haedrich 5/10 3258 days 2%
Nadja Guiliani 8/10 3262 days 2%
Elbrich 8/10 3262 days 2%
Jamie Serieux 7/10 3265 days 2%
Adele Jacques 9/10 3266 days 2%
Daniel Weber 6/10 3268 days 2%
Emily Noyd 8/10 3270 days 2%
Aparna Gula 10/10 3271 days 2%
Sebastiaan 7/10 3273 days 2%
Andre 9/10 3274 days 2%
Benedikt Hang 7/10 3275 days 2%
Yannick 8/10 3275 days 2%
S Black 9/10 3276 days 2%
Paul Larauze 6/10 3279 days 2%
Florence 6/10 3280 days 2%
Sarah Kovacs 8/10 3281 days 2%
Frenziska Schmid 7/10 3283 days 2%
Maud Livolsi 7/10 3290 days 2%
Lewis Whittle 6/10 3292 days 2%
Lukas Seager 6/10 3292 days 2%
Andrea Tabaka 8/10 3299 days 2%
Tina Rust 8/10 3301 days 2%
Joel Papak 8/10 3303 days 2%
Clemence and Pedro 9/10 3304 days 2%
Doms Wahlelr 9/10 3306 days 2%
Josef Biller 8/10 3306 days 2%
Justine Hoffmann 8/10 3307 days 2%
Friederike East 7/10 3307 days 2%
Mark White 10/10 3308 days 2%
Briony 8/10 3311 days 2%
Gabriel Siibers 8/10 3311 days 2%
Henry Wichler 8/10 3312 days 2%
Kyle Johnson 9/10 3314 days 2%
Niels Wezenberg 7/10 3315 days 2%
John Hamilton 9/10 3315 days 2%
Brianna Burd 9/10 3315 days 2%
Jessica Ruhland 8/10 3316 days 2%
Stula Vladimir 10/10 3317 days 2%
Cosmo Hartuna 7/10 3319 days 2%
Roland Fischer 6/10 3319 days 2%
Ross Holmes 9/10 3320 days 2%
Tilman 9/10 3322 days 2%
Petru 7/10 3323 days 2%
Fero Saarinen 6/10 3324 days 2%
Lauren Thompson 8/10 3326 days 2%
Meilin 8/10 3329 days 2%
Jonas Hoerning 10/10 3333 days 2%
Vanesha Patel 6/10 3334 days 2%
Mauricio Daniele 9/10 3334 days 2%
Sara and Antoine 8/10 3336 days 2%
Clare Pickford 6/10 3336 days 2%
Daniel Hill 10/10 3337 days 2%
Moritz Braun 7/10 3353 days 2%
Grischa Rodust 8/10 3360 days 2%
Chalie Dotesek 9/10 3361 days 2%
Julien Lafeville 7/10 3365 days 2%
Julia Huesam 8/10 3365 days 2%
Alexandre 9/10 3369 days 2%
Kev Zarka 6/10 3370 days 2%
Markus Wabing 8/10 3373 days 2%
Gessica 6/10 3406 days 2%
Simon Quass 9/10 3410 days 2%
Barthelemy 7/10 3639 days 1%
Brita Topp 10/10 3982 days 1%
Laim Thompson 8/10 3982 days 1%
Adriana 10/10 3990 days 1%
Pavel Jarolimek 5/10 3990 days 1%
Leonie Moeller 6/10 3991 days 1%
Doreen Gendel 8/10 3992 days 1%
Carla Oyarzun 3/10 3995 days 0%
Paolo Cases 3/10 3995 days 0%
Wolfgang and Christine 8/10 4000 days 1%
Helen 8/10 4013 days 1%
Olivier Carval 9/10 4015 days 1%
Hirsch Svenja 9/10 4016 days 1%
Mahr Svenja 8/10 4016 days 1%
Anna Guzewiez 9/10 4032 days 1%
Pier Durand 8/10 4036 days 1%
Serena Poggioli 9/10 4036 days 1%
Wayne Schist 7/10 4036 days 1%
Margreth Lydie 5/10 4044 days 1%
Laura Pleumeekers 7/10 4058 days 1%
David Brooks 10/10 4061 days 1%
Adrien Godeloup 9/10 4070 days 1%
Bet Dreno 8/10 4071 days 1%
Joachim 1/10 4072 days 0%
Pioter Jurkowski 7/10 4072 days 1%
Thomas Roche 9/10 4074 days 1%
Brian 9/10 4133 days 0%
hendrik king 9/10 4256 days 0%
Kiki Wykstra 5/10 4366 days 0%
Galen Licht 4/10 4366 days 0%
Yu-Ti Chu 7/10 4369 days 0%
Ton Martens 7/10 4369 days 0%
Joshua Perry 8/10 4374 days 0%
Molly Ladd 8/10 4374 days 0%
Michael Nolan 9/10 4378 days 0%
Julian Roots 9/10 4378 days 0%
Florent Corino 9/10 4382 days 1%
Amiot Cyriane 7/10 4382 days 1%
Annika 7/10 4382 days 1%
Jonas Herrmann 7/10 4382 days 1%
Matthieu Daveou 8/10 4382 days 1%
Julien Panossian 6/10 4382 days 1%
Raoul Montestruer 5/10 4382 days 1%
Alessa Ndra 8/10 4388 days 1%
Bjorn Hedmark 5/10 4389 days 1%
Evyatar Tulipman 7/10 4391 days 1%
S Curry 10/10 4406 days 1%
Ingrid 9/10 4450 days 1%
Reinier Timmer 7/10 4450 days 1%
Moorman 8/10 4459 days 1%
Stefan Roth 9/10 4484 days 1%
David 9/10 4498 days 1%
kevindang 10/10 4651 days 1%
Ruben Kunze 4/10 4733 days 1%
Sebastian Hol 9/10 4739 days 1%
Dick Stewart 8/10 4748 days 1%
David Beaumont 9/10 4755 days 1%
Beyeler 10/10 4760 days 1%
Nikita Sue 9/10 4765 days 1%
Schweiger 10/10 4767 days 1%
Jan & Marian 10/10 4846 days 1%
Konny 9/10 4850 days 1%
Waldemar Schuler 8/10 4850 days 1%
jule 3/10 4864 days 1%
Jack Potman 8/10 5066 days 1%
Jon_and_Family 9/10 5078 days 1%
Walker 9/10 5081 days 1%
Andreas Blessing 10/10 5089 days 1%
Gema 7/10 5092 days 1%
Avry Fabrice 6/10 5097 days 1%
Diane Johnston 9/10 5102 days 1%
Javier Munoz 8/10 5102 days 1%
Ben Akin-Smith 8/10 5103 days 1%
K Wallis 9/10 5108 days 1%
khs 9/10 5109 days 1%
Emma Ducat 9/10 5109 days 1%
Mr and Mrs Lambert 8/10 5116 days 1%
Andrew Koster 7/10 5122 days 1%
Bakker 8/10 5122 days 1%
Kimberly St Louis 8/10 5123 days 1%
Roel Wesstra 8/10 5129 days 1%
Seifert 10/10 5129 days 1%
Derek Woodward 9/10 5131 days 1%
Fabi & Sabi 8/10 5132 days 1%
Rosey834 8/10 5199 days 1%
Pete & Chris 10/10 5399 days 1%
Tony Masters 9/10 5462 days 1%
Hershell 8/10 5466 days 1%
Mike Robinson 9/10 5467 days 1%
Brent S 2/10 5468 days 0%
Zara Leyden 9/10 5476 days 1%
Judith 7/10 5480 days 1%
anon 8/10 5481 days 1%
Pierre Pilon 8/10 5482 days 1%
Jenny Omb 1/10 5487 days 0%
Frei Urs 6/10 5488 days 1%
Bryan Keddie 9/10 5498 days 1%
Leanne Rogan 5/10 5498 days 1%
Joanne Clarke 8/10 5502 days 1%
Wolfgang G 9/10 5508 days 1%
Thomas Signes 7/10 5529 days 1%
menzel 10/10 5547 days 1%
graemeh1 9/10 5548 days 1%
klinger 10/10 5548 days 1%
gereldineb 8/10 5558 days 1%
jennyb 9/10 5562 days 1%
Frank de Voogd 8/10 5568 days 1%
Jean Paul Mesnage 9/10 5574 days 1%
Hansjoerg Ehrmann 5/10 5575 days 1%
Daniel Alonso 9/10 5576 days 1%
Nigel Petrie 9/10 5587 days 1%
Tracy & Peter Cassidy 8/10 5603 days 1%
miniappleses 8/10 5625 days 1%
Josie Boyle 7/10 5736 days 1%
JanneP 9/10 5806 days 1%
Mikey 9/10 5813 days 1%
SablotniD 7/10 5817 days 1%
WiebkeS 9/10 5824 days 1%
Tanya 5/10 5825 days 1%
Jan 6/10 5825 days 1%
Viola 8/10 5827 days 1%
RowanL 7/10 5828 days 1%
VickiEngland 8/10 5836 days 1%
TomC1 8/10 5841 days 1%
AndyK 9/10 5841 days 1%
TatiamT 9/10 5841 days 1%
GillianK 8/10 5843 days 1%
EelcoK 9/10 5843 days 1%
Michael 9/10 5847 days 1%
soccaplaya14 10/10 5847 days 1%
Eugene 7/10 5849 days 1%
John 6/10 5851 days 1%
Tony 8/10 5856 days 1%
Middleton 4/10 5857 days 1%
Elise 8/10 5858 days 1%
Marie 8/10 5858 days 1%
ThomasS1 10/10 5863 days 1%
RasmusB 4/10 5865 days 1%
Simon 8/10 5870 days 1%
Phil&Joe 10/10 5872 days 1%
Marcus 7/10 5872 days 1%
Andre 7/10 5874 days 1%
Iris 9/10 5876 days 1%
Carla 7/10 5876 days 1%
Sandra 8/10 5880 days 1%
Schaffluber 10/10 5881 days 1%
Hayley 5/10 5882 days 1%
Con 2/10 5926 days 0%
felix 7/10 5927 days 1%
melissa 10/10 5933 days 1%
John B 5/10 5936 days 1%
Gemma 7/10 5974 days 1%
Henry 7/10 5975 days 1%
Antonella 10/10 5982 days 1%
Michelle 8/10 5982 days 1%
Laura 7/10 5991 days 1%
Sarah 8/10 6005 days 1%
Katerina 7/10 6026 days 1%
Erin 3/10 6026 days 1%
Mike Knight 9/10 6047 days 1%
Bronagh Mcartan 8/10 6056 days 1%
Dave 8/10 6067 days 1%
fgregory 10/10 6070 days 1%
Rhea 6/10 6116 days 1%
Georgina Mulligan 8/10 6127 days 1%
Karen C 7/10 6139 days 1%
Edmund Hillstone 10/10 6157 days 1%
Toby 6/10 6180 days 1%
Jennifer Baulch 9/10 6184 days 1%
Susan 8/10 6188 days 1%
Hoetnagels 7/10 6191 days 1%
Alan Bellerby 8/10 6194 days 1%
Sanne Jonker 7/10 6195 days 1%
Renske Tehurne 8/10 6199 days 1%
Benjamin Krein 7/10 6199 days 1%
Anne and Derek 8/10 6200 days 1%
James Davies 7/10 6200 days 1%
Naomi Horton 8/10 6201 days 1%
Roger Repolusk 8/10 6205 days 1%
Tony Wicks 6/10 6205 days 1%
Nancy Dol 8/10 6205 days 1%
Kristine 10/10 6205 days 1%
Kathy Hawey 9/10 6207 days 1%
David Buckley 8/10 6208 days 1%
Lena1 6/10 6208 days 1%
John Woodrow 8/10 6209 days 1%
Carmen Dolny 10/10 6209 days 1%
Haemnerli 8/10 6213 days 1%
Carla 8/10 6220 days 1%
Jim Curley 8/10 6220 days 1%
paulonline 7/10 6226 days 1%
Bex 6/10 6235 days 1%
Jenny Hulsebosch 8/10 6236 days 1%
Melissa Steedman 8/10 6247 days 1%
Tim 7/10 6248 days 1%
Falk Seidel 7/10 6251 days 1%
Hans Olthof 8/10 6251 days 1%
Anu 9/10 6254 days 1%
Anneli 6/10 6256 days 1%
purplekat99 10/10 6264 days 1%
Connor 10/10 6277 days 1%
Ad 7/10 6277 days 1%
Ann Westmacott 5/10 6282 days 1%
Paul Cowie 8/10 6283 days 1%
Ewen Maclean 8/10 6283 days 1%
Sarah Wilton 5/10 6283 days 1%
Arend v Dyn 7/10 6285 days 1%
Linda 8/10 6289 days 1%
Fiona 7/10 6289 days 1%
Ann 7/10 6290 days 1%
ranker_584 9/10 6293 days 1%
Christine 7/10 6293 days 1%
Nina 9/10 6293 days 1%
Anthony 7/10 6298 days 1%
Tom Clements 7/10 6298 days 1%
ranker_46 8/10 6410 days 1%
Pat Brewster 8/10 6410 days 1%
FrankOosterwijk 6/10 6495 days 1%
Kim 8/10 6495 days 1%
Helen 7/10 6526 days 1%
Heather 9/10 6526 days 1%
Helene 9/10 6538 days 1%
John 7/10 6538 days 1%
Giancarlo 6/10 6538 days 1%
Annette 4/10 6562 days 1%
John 5/10 6562 days 1%
Duncan 9/10 6567 days 1%
Jen 4/10 6578 days 1%
Rolf 8/10 6586 days 1%

Adjustments

Several adjustments to the weighted average are added to improve relevancy and credibility. These adjustments apply equally to all experiences that meet the criteria.

Sample Size Adjustment

No Adjustment

A reasonable number of reviews are necessary in order for the average to be credible and for an experience to take a prime position within the ranking tables. As such, experiences with only a few reviews have a moderated score. This does not mean that the experience or the reviews can't be trusted. The Interislander Ferry experience has plenty of reviews and does not meet the criteria for any adjustment.

Recent Reviews Adjustment

-1.51% Adjustment

There may be an adjustment if this experience hasn't received any reviews within the last 54 days. However the Interislander Ferry experience does not meet the criteria for any adjustment.

In addition, an experience's ranking score may be adjusted for each day there is no new ranking. After 1 day the adjustment comes into effect. The maximum number of days that can be adjusted for is 200 days. Due to the seasonal nature of many businesses, this adjustment is applied dynamically throughout the year.

The Interislander Ferry experience has been adjusted for 73 days. Adjustments are according to the following table.

Days Adjustment
70 -1.45%
71 -1.47%
72 -1.49%
73 -1.51%
74 -1.53%
75 -1.55%
76 -1.57%

Balancing Adjustment

7.13% Adjustment

Every experience's review score is adjusted to balance out the disproportional number of negative reviews that are contributed.

You won't be surprised to learn that disgruntled customers are more likely to leave a review than happy ones. They are motivated to share their experience and warn others. We consider this a good thing and it's why reading the reviews is important. However we've learned it can misrepresent the experience in a more overall sense.

We apply a balancing adjustment to counteract this effect and ensure the ranking score is a more fair representation of the experience. This adjustment is applied equally to all experiences.

Final Ranking Score

77%

The final ranking score once any adjustments, ratings, and rounding has been applied. This value is recalculated each day and a short rolling average is applied. Therefore it may not be precisely accurate based on the other values presented.